Fate stay night/WMG

WARNING: This page contains spoilers.

The Character Alignment in the Fate Stay Night universe is what the characters themselves believe it to be.
This would explain why a guy like Gilgamesh is marked as Chaotic Good and Assassin as Neutral Evil. They personally believe those to be their alignments.

In the anime, Saber is capable of returning to Shirou's world after her death.
Saber refers to her time with Shirou as a 'dream', and upon returning to her time says to Bedivere that she had been dreaming. Bedivere and her then discuss continuing a dream after it has ended, with Saber asking if you can pick up a dream where it left off when you fall back to sleep. Bediveire says yes, if you want it enough. Saber then says "my slumber this time will be a long one", and dies. Also Shirou's "I reach out for you but you aren't there"/"...we may grasp what we are reaching for" lines are sort-of telling. The last words spoken in the anime are "Are you dreaming now, King Arthur? Are you still dreaming the same dream?", or words to that effect, thus opening up the possibility that she may return to Shirou's time. Note that this is a question, so its open-ended whether or not she returns, but is still a salve for the tears of upset fans :)
 * Seconded, I just came to the same conclusion after thinking about it and was just going to add it to the page when I saw it already was there. Maybe it's just implied instead of being canon, but it sure is a comforting thought, I guess.
 * Of course, the canonical comforting salve still lies in Realta Nua: Last Episode. Whether or not Saber can return to Shirou's time, at the very least.

Shirou is actually a failed test subject for the Weapon X program.
This explains where he got his "Body of Swords" from. HOWEVER, due to sheer luck when he is deemed a failure he ends up not being "aborted" as a little fetus, but is instead chosen to grow and live a "normal" life, which is why he was sent to a needy family in Japan. Therefore, Shirou is a blood-brother to Wolverine and Deadpool.

The future where Archer came back from is that of Fist of the North Star After the End
Think about it for a bit, and it kind of makes sense: Emiya Shirou wished for a world in which he can become the greatest hero, didn't he now? It was said that the Holy Grail, being the Jackass Genie that it is, instead turned the world into one consumed by fire and warfare. The world of Fist of the North Star, set some twenty years after our present day, is one so torn by nuclear fire that society has degenerated into medieval feudalism, and a complete (thank Buddah) lack of Firearms meant that Martial Artists and Warriors had a place in the world once more (thank Buddah again). In this future medieval world, only Great Warriors with martial supremacy like Kenshiro could topple omnipotent Complete Monster maniacs like Souther: Shirou could very well have turned out to be one of the unsung heroes besides Kenshiro who has saved a Kingdom, but like the Bruce Lee Clone has lost EVERYTHING in the process of doing so. Taking one bitter look at the fallout-covered wasteland around him, is it any wonder he would come to regret the wish that made the world this way?
 * That doesn't sound like a wish Shirou would make...
 * You're quite right: It wasnt. In Fate Unlimited Blade Works (Soon to be adapted into a movie released in Imax in January), all Shirou wanted to be was "The Greatest Hero Ever." The Grail, however, is the kind of Jackass Genie that warps the wording of your wish so all that you get is the result, spirit be damned. What that evil artefact did was turn the world into a war-torn hellhole (it was not specified how), thereby forcing Shirou to become the Legendary Hero  just to save it. And then he travelled back in time to set things right...
 * No, I mean, that doesn't sound like a wish Shirou would make. Mostly because it's doubtful he'd make a wish at all; he's adamant from the start that he has no desire to have a wish granted, and he's inherently suspicious of an object that causes so much bloodshed just by its mere existence. Perhaps, in the extremely unlikely case that his suspicions are never heightened and he never finds out about the Grail's corruption (which would require very exact, highly improbable conditions), he might try to make a wish, but it's not terribly likely. More likely would be someone else getting the Grail first and accidentally causing the apocalypse. Keep in mind, we know what Archer went through, and why he wanted so badly to kill Shirou...
 * No offence was meant, sir/madame/miss. I was referring to the "original timeline" from which Archer or rather  came back from, not the current Unlimited Blade Works timeline in which   won't make the same rash-and-stupid mistake/wish.
 * None taken at all (being offended didn't occur to me, honestly). Still, I'm saying that's a really unlikely prospect. We know Archer's motivations; he contracted himself to the world to save people and was executed. He died confused, but without as many regrets. His insanity-inducing regrets didn't come about until he'd been forced to kill and witness death and destruction that he could do absolutely nothing about over and over and over again...much later than his actual death and any prospective apocalypse he may have caused. Again, not saying that a wish on the Grail couldn't have brought about the Fist of the North Star verse (if Shirou failed to stop whoever it was, and went about saving people After the End prospective-Archer style), just that it's really unlikely that Shirou himself was the cause.
 * On a different but related tangent... if Servants are actually massively-powered-up reincarnated heroes from both the past (like Saber-chan is) and the future (like Archer is), and if the Fate Stay Night - verse is crossed over with the Fist of the North Star - verse... Imagine how practically already-won a Grail War would be for a master who has someone like Souther, Raoh or Kenshiro as a servant... oh even Saber-chan (much as I love her and wanna hug her all day long) would be so fucked at that point.
 * Not all Servants are powered-up. Saber and Berserker at least are actually weaker than in life. Kenshiro would be good, but not invincible.
 * Heroic Spirits can't come from the future, only Counter Guardians, so Souther and Raoh are out of the question. Kenshiro, however...ouch, he'd be an incredible Berserker.
 * Hmm, considering his weapon of choice, I think his character class would either be called "Monk" or "Boxer."
 * Save for the fact that this is the Holy Grail we're talking about, not Final Fantasy XI.
 * We actually don't know how power-up they are. It's mentioned that a lot of them retain similar strength to when they were alive. These are people who would go around doing things like killing dragons (saber) during their life.
 * In that case, oh boy Kenshiro would most definitely demolish Saber-chan even if he wasn't a servant.
 * What? Since when can Kenshiro move around at mach 3 and be able to fire giant beams of light that destroy everything?
 * Ah, you have not seen the second Fist of the North Star TV series or the Shin Kyuseishu Densetsu movies of yet, in that case. He does the energy beams in the former and the blinding-speed in the fifth movie (Kenshiro Den) of the latter.
 * One very important thing that's not pointed out yet: Do servants have "Keiraku Hiko" or "Acupuncture Points" like normal humans do? Because Souther was able to shrug off Hokuto Shinken because the pressure points on his bodies are reversed compared to that of a normal human beings. If the servants have Keiraku Hiko on their bodies, then they are already dead (sorry... chuckles); but Kenshiro is going to have a HARD time beating them as he did Souther if they don't.

Archer is not Fate Shirou.
Official sources have said that Archer's circumstances are most similar to Fate Shirou but everyone this troper has spoken to seems to interpret that as "Fate Shirou becomes Archer". Notice one major difference, however; Archer was eventually overcome by the evils of mankind and doomed to witness the evil that men do for the rest of his existence. But Fate Shirou has not only defeated those same evils, he's defeated the physical embodiment of those evils in the form of Angra Mainyu by pure force of will. Compared to Archer, who eventually started sacrificing the few to save the many like Kiritsugu, Fate Shirou is too idealistic to even consider making that sacrifice and so will not become Archer.
 * Well, that's the key, isn't it? Eventually. Archer started out as idealistic as Shirou, after all, but found out that things weren't that convenient eventually. Sooner or later he probably got forced into a position where he couldn't choose at all. Anyway, it's been a while since I played the VN, but as far as I remember Shirou didn't destroy the true grail (which isn't even touched upon outside of Heaven's Feel), he merely escaped from the mud using Avalon and closed the conduit between the true grail and Ilya -- but that's just semantics. Anyway, I don't know if this is even WMG because Realta Nua gives Fate Shirou a very non-Archer-like ending (either that or he's undergoing Instrumentality, because as we all know you can't have a WMG page without name-dropping that one).
 * In the onsen omake of the VN, Taiga worries that Fate Shirou was going to become like Archer. Illya states that in all three routes Shirou becoming Archer is a very low probability. Then again, she also states that she was there for him in the Fate route and Taiga worries about Shirou being helped by "this devil child."
 * That would explain why Archer doesn't seem to possess Avalon, Shirou being able to use it at will -- as if it were his own Noble Phantasm and for apparently no mana cost -- is unique to his uber-idealistic Fate incarnation.
 * No, no no no no, that's because Archer isn't the main character and thus aren't entitled to Deus Ex Machina copouts when pushed against the wall. In all seriousness, though, Archer knows what Avalon is, which only Fate Shirou knows. It's also stated in the side materials that he had to live through Ilya wasting away and dying after the Fifth Holy Grail War ended due to her homunculus anatomy, something which again only will happen to Fate Shirou.
 * Or will it? If Shirou is capable of tracing Avalon, what's preventing him from implanting a copy in Ilya and halting her premature death? Even if it isn't a perfect copy, Shirou can trace the thing as many times as he needs. As to why Archer!Shirou didn't use this method, maybe he only discovered Avalon after Ilya's death, or while he was a Counter Guardian.
 * There's a difference between Deus Ex Machina and Chekov's Gun...
 * There's no real reason that the three stories presented are the only three possible ways the story unfolded. After all, FHA follows a different continuity altogether, the details of which are not entirely clear.
 * My current theory is that Archer is form "Bad End 30". This ending has Shirou throw away his emotion to become a hero, and allows Rin to murder Sakura for the greater good. Kotomine prophesizes that Shirou will easily kill all the other Masters, even Rin, because he is dedicated to a higher goal now. This sounds an awful lot like Archer. And in order to defeat Servants, Shirou would probably need to master his projection magic and reality marble, making him dangerously close to Archer by the end of the Holy Grail War.
 * That doesn't really work, though. Shirou never abandoned his goal to save everyone he came across, hence why Archer's past is supposed to most closely adhere to Fate (he had nothing to challenge his naive, borrowed ideal). Even when he was betrayed and executed, Shirou still held hope that as part of the Counter Force, he'd be able to prevent disasters and save people. He became the disillusioned Archer only after he realized that his entire purpose was an eternity of troubleshooting mass murder, and that his ideal of saving everyone had led directly to his self-destruction.
 * I was under the impression that Archer is from the unreleased Ilya route where he fails to save Saber from her endless loop, Rin and Sakura both die, and all to save Ilya who slowly wastes away anyway and dies not even a year later. Which leaves him with no one to support him, and once he's martyred by an ungrateful humanity, poof. Instant Archer.

Archer is Shirou who has lived through all 3 routes and a couple more possible routes.
In HF, Archer knows the shadow, but when Saber does not recognize it, he says something to the likes of "You have not seen it yet in this reality" (IIRC). Also he knew that his arm was transplantable, something Shirou wouldn't even think of if it never had happened to him (or do you think, Fate Shirou would know that it would work?) So he lived through HF. Furthermore, Archer tells Shirou in UBW, that he one lost an arm by projection, but in none of the routes Shirou loses his arm by projection. It only is swallowed by the shadow. And it is highly unlikely that HF Shirou or UBW Shirou would do that. Because Fate Shirou has not figured out really anything about projection after the route, he is the only one who probably would lose his arm. Other remarks of Archer would make one assume that he knows of the different routes (one in particular on UBW). So in conclusion, Archer has knowledge he could only have if he lived though more than one route. So why should he not have lived through a bunch of routes?
 * He tells Saber "You're not a guardian, yet. You must not have fought something like that before," then he tells Shirou that this is no time for personal grudges (in other words, "I don't have time to kill you now") and muses that he might be able to "finish it beforehand" this time. I always interpreted that as him having encountered something like Angra Mainyu before, and the Shadow was the reason he, as a Counter Guardian, was summoned (and he might be able to avert disaster before the situation goes to hell, instead of cleaning up afterwards like he usually does). As for the arm, he might not have actually known it was transplantable, but he had a very good reason to suspect it might (since it was his arm, after all). Really, the simplest answer is that Archer didn't live through any of the three main routes, but a single unlisted one.
 * Incidentally, in UBW Archer states that his arm was paralyzed the first time he broke through and used projection (which is what has just happened to Shirou in that route) and that he's lucky that he didn't burn completely out (which I presume is something he'd be well aware of even if it never happened to him).
 * My take on it is that UBW resembles it closest, but probably depends on what happens from there. It's implied in the UBW movie that Rin's presence in Shirou's life will prevent him from walking Archer's path.
 * Actually, if it resembles any one of the three routes, it would be Fate and not UBW. UBW relies too much on Archer's presense and actions for it to make sense that it would be similar to his own timeline, and further Ilya is stated to have survived the Grail War in Archer's time. Plus, UBW Shirou has come to understand his ideal in a way that Fate Shirou did not, and he has Rin there to guide him, whereas Fate Shirou does not have Saber. Most likely, in fact, Archer's past was something like Fate, but with a weaker connection to Saber and, probably, without him being able to persuade her to give up her ideal (most likely instead being forced to order her to destroy the Grail like Kiritsugu had had to).

Saber was originally intended to be the Player Character, but was turned into the main girl for Fate when genders were swapped
Earlier art showed that Saber was originally going to be male, and Shirou was originally going to be a Meganekko named Ayaka Sajyou. Considering the nature of mana regeneration, and what happens to Saber in the other routes, it doesn't seem so hard to fit it into that kind of game. Granted, it was probably changed due to storytelling convenience, or something like that, but in retrospect, it seems plausible.
 * Word of God says as much. Originally, Saber was going to be male and the "Shirou" character a female. And that's how King Arthur ended up being a girl.

Shirou's birthname was actually Sajyou.
See above theory for clarification.

All the Servants are magical constructs with false memories shaped by public perception and their Master's own outlook; Assassin was the only one who figured this out.
The Servants include a lot of beings who are just as dubious in terms of actual existence as Sasaki Kojirō, and yet all of them were real. However, there are some odd discrepancies: the rider of the Pegasus is not Bellerophon, and something else is; Mordred calls Saber "father," which fits with the Arthurian mythos but not with Arthur being female. Further, their abilities are explicitly beyond those of any living human, and (based on Archer's actions in Unlimited Blade Works) time paradoxes do not form if they use their time on Earth, let alone the Grail, to alter their own past lives/deaths. Most probably, every servant is just a magical construct, but all save the deeply flawed Assassin have fake memories so convincing that they think themselves real.
 * Servants are copies of the souls of Heroic Spirits, taken from the Throne of Heroes using a weaker form of the Third Magic. Saber is the exception; she made a contract with the world to gain the Holy Grail in exchange for being at the world's beck and call afterwords.  Assassin is a "fictional" hero because, as a Spirit herself, the one who summoned him, Caster, could not call a true Heroic Spirit. Some wandering spirits were gathered and took on the identity of Sasaki Kojrio.
 * ... Are you aware that this is Wild Mass Guessing? The place where people discuss things that twist, warp, and occasionally disregard canon? For fun?
 * Silence!!!
 * TYPE-MOON fans are... zealots, to say the least. Fanatics, one might say.
 * You would hope that a person editing a WMG page would be a troper before a crazy fan, but... yeah. This is not the place for "Stop Having Fun!" Guys.
 * The presented theory has the pretext of being a serious suggestion. It's not "stop having fun" if there's no indication the troper is actually doing it for fun.
 * And this is nothing compared to the power level arguments and shipping Holy Wars for an extra-special layer of TYPE-lunacy. In the case of shipping, it's somewhat understandable because those fans treat Shirou as a Featureless Protagonist at least when it comes to the sex scenes. It ain't Shirou who's the one recharging the ol' mana there, wink wink nudge nudge.
 * This theory has one major hole; It would be highly unlikely that Rin would create a "future Shiro" for her servant for two reasons:
 * 1) All indications point to their being just classmates, barely acquainted with each other before the grail war; barring some kind of bizarre crush, she had no reason to imagine him as her servant.
 * 2) They share the same reality marble. Archer used it before Shiro ever knew he had it, and they are supposed to be unique to each individual. There was no way for Rin to know that Shiro had a reality marble or what form it would take.
 * That wouldn't necessarily conflict with this theory, since the theory doesn't have to apply to Archer. His memories are real, and unlike the others (besides Saber, who's in a similar position), he also has memories.

All the knights in ancient England were women.
The only three we see up close are Mordred, Arturia, and Bedivere. Yeah, I know that Lancelot shows up in Fate/Zero, but consider this: do we ever get a good look at the body under that armor? Clearly, the gender roles in England changed places during the intervening 1,000 years; the myths were changed to reflect the new norms. Saber thinks she was raised as a man because, as an incompetently-summoned Servant, her memories are a bit garbled.
 * At least one Rin/Saber Fanfic genderbended everyone that lived in Arthurian times.
 * It would make Guinevere... William? It changes a lot of perspectives.
 * Jossed. Though Lancelot comes in Fate/Zero, when the novel gets a Drama CD treatment, who voices him? Ryotaro Okiayu. The man behind Zero or Byakuya Kuchiki. That's one damn manly voice.
 * Maybe Lancelot cross-dressed?
 * Would that mean that Lancelot was a man pretending to be a woman pretending to be a man?
 * This troper's gender-specific pronouns hurt.
 * It makes more sense that Lancelot is a man, because then we have an alternate interpretation of Guinevere's affair with him. After all, if Arthur is gender bent, then Saber would have married Guinevere simply to maintain the illusion that she is a he. Which would strain their relationship somewhat in the bedroom.
 * Another possibility is that he wooing Guinevere with Arturia's blessing. Guinevere was straight. Sorry. So Arturia let them get together. After all, it might result in a more easily explained child than Mordred. But it was discovered by others, and Arturia was silent; since explaining how she was a woman would be far more damaging to Briton in her mind then letting everyone think Lancelot and Guinevere were betraying "him". (Yeah, that didn't turn out so well.
 * According the Side Materials (which might not be considered strictly canon) both Bedivere and Mordred are male. In Bedivere's case it might be intentional to help maintain the illusion that a very pretty girl is in fact really a man.

Archer cannot summon Noble Phantasms belonging to other Servants currently in the world.
This is why he doesn't just whip out Avalon, Gae Bolg, or some similar trick when it seems like it would be useful - all of those are spoken for in the present reality. And, being Shirou, he only knows about a few Phantasms belonging to servants not in the Fifth War.
 * He creates copies of Phantasms; he doesn't summon the real ones, that's Gilgamesh's shtick.
 * Semantics. Clearly, he does not create the wide range of Phantasms it seems like he could - he doesn't even create Caliburn to kill Berserker multiple times with one hit, and we know he's learned that trick. If he can only create "unique" items (that is, ones which exist nowhere else in this world), it would explain this lack.
 * Caliburn is only that powerful when Saber is wielding it. In the hands of anyone other than its destined owner, it's fairly weak.
 * Makes sense, except that the rule has to be lifted under the Reality Marble - Unlimited Blade Works. There, Archer threatens to trace, then break, Excalibur itself. Note that Archer's best ability is his ability to trace a Noble Phantasm, and then overload it with magic, converting it into a Broken Phantasm, which is exponentially more powerful than its original form, at the cost of the original Phantasm's destruction - which is quite meaningless to Archer. The general theory is true in the other two paths, but not Unlimited Blade Works.
 * Doesn't he duplicate Gilgamesh's phantasms despite Gilgy still hanging around?
 * Gilgamesh's Noble Phantasms are Ea and Gate of Babylon. Archer has no need to duplicate Gate of Babylon; he can already make all those weapons, anyway. He explicitly cannot duplicate Ea, which isn't a normal sword. (That's why Shirou nearly panicked when Gil tried to pull it out in UBW - it's the only sword he couldn't counter).
 * But didn't Shirou replicate Berserker's sword in Heaven's Feel? With Berserker in front of him. It probably has to do with the fact he isn't as powerful as heroes of the past, and can't use their weapons effectively.
 * Well, that one isn't a Noble Phantasm either way. It's just a big piece of rock.
 * You realize that Archer specializes in swords, right? That means that Lancer's Gae Bolg isn't a feasible weapon for him, nor is Rider's chain nail, nor duplicate Rider's Pegasus because it's a living thing, could trace Caster's rule breaker, but for the most part it would be pointless, Berserker and Assassin's weapons aren't Noble Phantasms, the techniques are, Avalon is probably too mana-expensive to just pull out whenever considering that Rho Aius is probably cheaper, he could copy Saber's Excalibur but he would die of mana overloading his circuits (Nasu Interview, Heaven's Feel), and generally, he is most skilled with Kanshou and Bakuya.
 * Archer can make Gae Bolg and other weapons besides swords. The spear shows up when Shirou thinks about the many Noble Phantasms in his memory. Archer can project furniture and defensive items like Rho Aius as well. All Unlimited Blade Works does is make projecting swords easiest, it can also apparently provide material for other projections, at more significant mana cost. It's not entirely clear what sword means here, either, it could just be weapons of any kind. Otherwise Shirou would have been skewered by all the non-sword weapons in Gilgamesh's treasure house, like his halberds and spears and hammers.
 * Actually, Gil does this deliberately. He wanted to test his weapons against Shirou's, so he used the same ones (yes, he's an idiot...). Shirou can indeed trace non-swords, though.

Shirou/Archer in the Anime is following a Stable Time Loop.
He didn't come to Grail War to kill his past self; he came to cause the events he knew would happen, including saving his own life (along with those of Saber and Rin). While in the vicinity, he gave himself crucial lessons in discipline and Tracing. Clearly, he is not the dark future version of Shirou from Unlimited Blade Works - otherwise, he would have walked away. Since he was both willing to sacrifice himself for others (without it costing Rin a seal) and unwilling to kill an innocent, we can assume that all those lectures he gave Shirou about ethics being a weakness were just a clever ruse to shore up his own convictions in the past.

Kirei wanted to destroy the Grail the whole time.
Kirei has no ethical compunctions against using a magical weapon, but he sees the Grail as so powerful, it makes people weak to depend on it. Like the elder Emiya, he would have ordered Gilgamesh to destroy it had he gotten the chance. He planned to do much the same thing at the end of the Fifth Grail war, but the chance to tear down Emiya's son was too good to pass up, so he lied in order to make Shirou suffer. This is why he didn't try to make a wish with the manifested Grail while Shirou was busy fighting off the Final Curse.
 * Gilgamesh, on the other hand, really did want it and would have killed Kirei had he known.
 * There's no way he would do that - Fate Zero shows that his only pleasure in life is the misery of others, a tainted grail is the perfect tool to create that. In Heaven's Feel, it's revealed that his chief purpose was to try to let Angra Mainyu be born through it (for various reasons). Also, he never lies as a rule - he just withholds anything that he's not specifically asked about. This is just as devastating, and it's far more amusing once he says "you never asked".

One of the early Grail Wars caused the Great Tokyo Earthquake.
Because not enough works of fiction are claiming credit for that anymore.

One of the future Grail Wars will cause the Second Impact.
Well, it does bring devastation to nearly everybody... except some guy named Adam, who uses the Grail and wishes to become a massive, powerful, inhuman monster.
 * Don't forget about Lilith, his servant!
 * What class was Lilith?
 * Avenger.
 * Kirei's allies went on to form SEELE to recover the power of the Grail.
 * Oh, good. Now we've opened the doors for a Gendo/Kirei Slash Fic.
 * Don't forget Zouken.
 * Um, didn't Second Impact occur in the year 2000, as opposed to the game being set in 2005?

Archer's home timeline is one where Shirou never entered the war
Instead, Rin succeeded in summoning a Saber-class servant. Without Shirou's involvement, the resulting war was much bloodier, had a high degree of collateral damage, and resulted in the corrupted grail fully manifesting and causing widespread devastation. Almost everyone he knows and loves is killed in horrific ways. Lacking a servant or any instruction in tracing, he finds himself all but powerless; in desperation, he forms a contract with the world that destroys the grail and dooms him to life as a counter guardian.
 * Shirou had to have figured out how to use tracing (maybe even his Reality Marble, though his chant seems to indicate otherwise), at least; it was his only weapon while he was out being a misunderstood wandering hero. Still, he likely wasn't as powerful as the much more experienced Counter Guardian-Archer, though. He needed that contract with the world to destroy the Grail...
 * Archer won the grail war and used it to become a servant in his timeline. Due to the magical nature of the Throne of Heroes, he can be summoned at any point in any timeline.
 * No, Archer won the war (his circumstances were described as being closest to the FSN anime) and went on to get involved in more and more conflicts, becoming more and more like Kiritsugu. At one point, he was trying to save people from a natural disaster (not even a human conflict), but couldn't because of his lack of power; at that moment, he forged a contract with the world to save less than 100 people. He went on as usual after that until he was eventually used as a scapegoat and executed by somebody that he saved.
 * As a side note, he would never hurt Illya because, in his timeline, she died a year after the Grail War; his inability to do anything about it was one of the things that motivated him to become like that.
 * Archer recognised Saber, which led to his near fatal blow in Fate and HF. Which means the same Saber was summoned in the original war. And Emiya Shirou is really the only one who can summon her, because of Avalon. It's interesting, in fact to speculate who Rin's servant would have been in this timeline, or indeed if she would have had a servant, since she was doing stuff wrong by not using a trigger. (Which her jewel was with Archer.)
 * Stable Time Loop There is no original timeline. Rin always summons Archer.
 * But there are three different mutually-exclusive routes! I think Archer would remember that he'd been a presence in his original timeline. That's not what Stable Time Loop is about at all.
 * Maybe it's a stable time loop inside a non-stable loop?

The endings of Fate and UBW are bad endings
One word: Zouken. He's not even confronted -let alone stopped- in any route but Heaven's Feel, which means that he'll go through with his original plans in the other timelines. This means that Sakura is still infected with the crest worm, and thus still under his control and open to his abuse and manipulation; Zouken will continue with his original plan to gradually turn her into a vessel for the Holy Grail over the course of the next ten years or so.

These "good endings" are bad enough for poor Sakura: she mourns over the death of Shinji in Fate; in UBW, she's forced to watch Shirou, who's basically the only source of joy in her life, fall in love and move to London with Rin. Worse, the summoning circle for the Holy Grail under Ryudou Temple is still intact, and Zouken's greatest potential adversaries (Rin and Shirou) are oblivious to his existence and seem convinced that they've ended the War. The only person who was on to him (Kotomine) is dead.

The Fate and UBW timelines will see another Holy Grail War after ten years or so. That future Holy Grail War will likely involve a Dark Sakura...
 * That's assuming there's going to be another Grail War. Even if there is, it's not likely to be another anomalously early one. (The Grail also wouldn't be at Ryudou Temple, incidentally). As for Sakura...sheesh, give the poor girl some credit; she's stronger than she looks. Otherwise, she would have snapped long before Angra Mainyu came along. She's still better off than she was at first in both Fate (abusive brother dead, still close to guy she loves) and UBW (abusive brother reforms for the better).
 * Exactly why wouldn't there be another Holy Grail War? All that Shirou & co. achieved in Fate and UBW was destroying the summoned Grail, which is no different from what Kiritsugu did a decade earlier. There has not yet been a good explanation for why the Holy Grail Wars would have ended for good with the events of Fate or UBW. As for the odds of another early Grail War, you have a point; but Kotomine said that this unusually early Grail War was the result of lots of magical energy from the previous Grail War remaining around and creating circumstances suitable for the next war, which was in its turn the result of the destruction of the previous Grail... The similar circumstances might just force another abnormally early Grail War. And as for Zouken's schemes: his decision to turn Sakura into a vessel for the Grail was definitely not taken on a whim - he turned her into a vessel for the Grail when he implanted the shards of the previous holy grail in Sakura's body ten years before the events of FSN; and in his last face-to-face conversation with Shirou, he clearly says that it was his original plan to gradually change her into something like a Holy Grail over several decades. Indeed, Zouken was forced to play his hand and rush things in Heaven's Feel, but he would carry on with the original plan in the Fate and UBW timelines, too.
 * Kiritsugu's attempt had some weird circumstances attached, which might discount an exact duplicate scenario. That particular Grail had already been used for a wish (sort of) and overflowed into the city before (or when) Saber shattered it. Regardless, even if the Holy Grail War were to somehow start again, you're dismissing Rin and Shirou too easily. They participated in the war and believe it ended; but even if they're wrong, they're not likely to stand aside and let it go on. It would also be impossible for them to not be aware of another war. Even disregarding Rin's eventual connections with the Mage Association and the likeliness of a Church supervisor seeking them out, the next Grail summoning would take place at the Tohsaka mansion. Also, while it's probably not likely, there's always the chance that the Mage Association or the Church would finally consider the War to be a little too apocalyptic, set aside their lassez-faire attitude, and take steps. Ditto the Einzbern family and their obsession with the Third Sorcery; they might finally write that attempt off as a failure. As for Sakura...again, see Shirou and Rin. Especially in Fate, they're not likely to break off contact with her, which offers some protection from whatever Zouken might deign to do...
 * To add to that, if there isn't another abnormally early Grail War then Zouken probably won't last long enough to see the next one. The time his body lasts is now down to a mere couple months and deteriorating rapidly. It seems like this is pretty much his last shot.
 * He himself says that though he will have many more chances in the future. However, he also says that Sakura won't last long enough for it to matter. Still bad for her.
 * Waver Velvet (Rider's master from Fate/Zero, the 4th war) shuts down and dismantles the grail system after the 5th war, so even in Fate and UBW there aren't going to be any more Holy Grail Wars.
 * Also, since Heaven's Feel has been announced to be the canonical route, this appears at least partially true. Well, depending on your definition of bad ending. The bonus Tiger Dojo says (or at least hints) it; and it's the only ending that has a definite 'the end' screen. Finally, F/HA most closely resembles the HF route.
 * What the Tiger Dojo is saying is that HF's ending is the "true ending of FSN" because there are no more endings after it (besides the Onsen omake). To reach HF you had to see the endings for Fate and UBW.
 * This is the Nasuverse, all endings are canon.
 * A 'canon' ending would only mean the storyline they build sequels out of. Judging by Tsukihime/Kagetsu Tohya (which supposedly follows Satsuki's normal end, which she seems to be dead in) mashing together plot points from all the other routes, it seems likely that they would pick and choose details for what is the final confirmed final end. Stuff like Shirou/Saber, Archer revealed, maybe some stuff about Zouken and a hint into Sakura's backstory while confirming that it's not going to continue.
 * Actually, Melty Blood is the one that's supposed to follow Satsuki's ending, and it's comparatively straightforward. If Kagetsu Tohya follows any ending, it's either Arcueid's or Ciel's Good ending (since Arcueid is still around)...'course, that's just the setup; the rest of the game plays hopscotch with route canon.
 * Details are only hinted at for Satsuki's route, so anyone could have made an appearance there. Also, it seems a fair assumption that the basic gist of Kagetsu Tohya is canon in that Len made him dream stuff, he saw and fought his nightmare Nanaya and made a contract with Len. Those elements all turn up in Melty Blood, implying a direct sequel. All five main heroines are around in both, with Satsuki's status left very vague - this troper can only remember one reference where in Arihiko's side story, he mentions that she also fully recognized Shiki's proximity to death - meaning she could be dead or alive there, which seems to be the difference between her Normal and True ends. To avoid getting too off topic, just going to say that it seems unlikely Melty Blood wouldn't also include Kagetsu Tohya based off that, and therefore it's rather difficult to exclude it from following the same end.
 * True. Since Melty Blood has Nero and Roa (instad of SHIKI), it would probably be a "Near Side" route, and so explain Arcueid's presence in the real world of Kagetsu Tohya (aw, man, I hope that doesn't mean Satsuki's True ending is like Ciel's Good one). If nothing else, Melty Blood would follow Kagetsu Tohya simply due to the weight of all the Shout Outs. That would make, say, Hisui's and Kohaku's Arc Drives make a lot more sense. As for what this means for Fate Stay Night...maybe the "canon" route really belongs to Ilya or Taiga!
 * Hey guys, are you forgetting the talk the girls had in the Plus Disk? In it, they say the canon ending is Arc's Good Ending, with things from the others' routes happening in the middle of it. There's no reason Satsuki isn't one of those "other routes".
 * Just out of curiosity, but exactly where is this (that stuff about the grail system being dismantled) shown or mentioned? Is it in Fate/Zero, Hollow Ataraxia, or some other source?
 * Character Material.
 * Rather than being bad endings period, the Fate and UBW routes are bad endings for Sakura. In them, she ends up becoming one of the 27 Dead Apostle Ancestors because she ends up succumbing to the Shadow. Eventually, this leads to Shirou having to kill her. Awwww....
 * But, without the Holy Grail (and thus, without Angra Mainyu), there's no Shadow to succumb to.
 * She still has those worms hybridized with the pieces of a past lesser Grail. That has to count for something...something bad...
 * They probably mean her hair and eye color are stuck the way they are, and she can still use Matou-style magic (and her mana capacity might still be enormous). Once there's no Greater Grail to connect to, though, being a Lesser Grail doesn't mean much. Granted, Zouken could still probably do unspeakable things to Sakura, but since his plan to get the Grail failed without retry, he really doesn't have any reason to.
 * Presumably Shinji has stopped even in UBW, and by this point she hates Zouken too much to really care about any more abuse he throws on her as Zouken himself notes. As a side note, that's a really depressing form of good news, isn't it? Er... Anyway, Shinji and Shirou were the only ones who could break her, the Shadow is gone so all she has to deal with are worms and a Zouken who probably won't last too much longer. Seems likely that considering how well she does with the worms active it doesn't really matter if she's still infected or not. Except she has no ovaries, but yea!
 * To build on from the original, maybe a bad ending version of Fate accounts for Archer turning out the way he did. One year on from the fifth war, the war happens again. Things proceed like Heaven's Feel this time, Archer, working with Tohsaka is forced to earn his powers in order to project Zeltrech or Excalibur to defeat Sakura, I guess killing Sakura this time. Ilya sacrifices herself in the end so Archer would survive. This is why Archer recognises what the black holy grail is.
 * His backstory is based mostly on Fate. He knows Saber's true identity, knows about Rule Breaker, Ilya and lots of other stuff. On the other hand, he also knows who Caster is, and her Phantasm doesn't really give her away. Possibly a Fate ending where things turned out somewhat nastier.
 * Archer is Shirou from the anime.
 * um..., doesn't Zouken die in UBW? I'm pretty sure Shinji uses Gil to kill him.
 * Zouken dies a few times in Heaven's Feel, too. It only sticks once.
 * There are a few (fairly subtle) implications in the Fate epilogue that Ilya dealt with Zouken, using her Genetic Memory of Justicia to push his buttons. Admittedly, the only real hint is that Sakura only cheered up after interacting with Ilya a few times.
 * In Fate, Illya doesn't actually know about Sakura's situation. She only finds out in HF because Sakura starts absorbing servants. It's not impossible, though, that she'll discover the truth.
 * I was rather hoping that, given the Multiverse nature of the Nasuverse, that Zouken didn't even exist within the other two routes....Just hoping...
 * That doesn't work, I'm afraid. Taiga explains at a point in UBW that Sakura's grandpa had called.
 * More to the point, it doesn't make any sense, unless Sakura's entire personality and background changes depending on whether you decide to walk her home and cook another dish for dinner.... Without Zouken, Sakura would have just been Rin's (possibly) oblivious younger sister (or, else, she'd have been given to someone else to look after and train), and she'd have had black hair. So, either Sakura being Rin's sister is only true in HF (so you have two completely different people who act in exactly the same way), or Zouken exists in them all. There are a lot of other hints too (Shinji goes into the basement in UBW, and Gil is crushing worms).

Saber will become a true Heroic Spirit.
Yes, originally she was only a Servant because of a magical deal she made with Gaia. When she gives up on the deal, she stops being a Servant....but she's still freaking King Arthur. She goes back to her own time and dies, and her Legend lives on. Given the immense amount of reverent storytelling, she's a shoo-in for the Throne of Heroes, whether she wants to be or not. Of course, whether this would be her consciousness or some kind of magical clone depends on your interpretation.
 * Isn't that canon? She becomes a true Heroic Spirit after she gives up seeking the Holy Grail and dies. Unless you go by the Realta Nua ending.
 * She probably won't - her contract with the world was that she would get the Grail before she died, meaning that she can never become a Heroic Spirit until she gets it. In Fate route (and possibly UBW good), she gives up attempting to get it for good and thus effectively nullifies the contract and moves on (then Realta Nua?). In the other routes, she'll probably just stay in the Nasuverse's version of limbo until the system dies or she gets it - in which case she would become a Heroic Spirit. Heroes have to have some unfinished desire to be part of that system (even if they don't explicitly make a contract), such as to keep fighting worthy opponents or get everything or conquer the world, etc.
 * The contract kept her from being a heroic spirit simply because she couldn't die. She certainly seems to fulfill most of the other criteria for the Eirei...aside from maybe the unfinished desire thing (does that explanation include Medusa and Angra Mainyu?).
 * They just had a lot of resentment against humanity, which technically counts, as well as explaining a good amount of the anti-heroes. I figured that because it's explicitly said that heroes go for the grail because they want something, although now that I think about it only two seem to actually hold themselves to that. And I have no idea why Assassin (not Kojiro) was part of the system - the real Assassin class was specifically required to be one of the Hassans, since the entire point of true assassins is that they're pretty much unknown. So who knows why the hell they're in the Throne of Heroes...
 * Assassin's interesting to think about...well, we've seen two criteria for determining what spirit gets summoned: possession of an appropriate artifact is one (Saber with her scabbard, Archer with, Lancer with his earrings, etc.) and/or personal compatibility (I suspect that Rider, and maybe even Caster, were summoned this way). We can probably rule out the second in Caster's case; with her personality, she's more likely to summon Lucretia Borgia than Sasaki Kojirou. Therefore, it's most likely that she had an artifact. After all, if Fate/Unlimited Codes counts as canon, Caster knew immediately who Assassin was supposed to be. My guess: she had Monohoshizao, reputed to be Kojirou's sword, and called him specifically. Since he doesn't exist, the Grail plunks a random spirit or four from somewhere that kinda resembles him and delivers him to Ryudou, where Caster hands him the sword and says "Don't let anyone cross this line" (Assassin's response: "Ummmm...'kay"). As for class, we've seen that some spirits qualify for more than one class (Heracles, in particular, can be any non-Caster class). Since he's not a heroic spirit, Assassin's not bound by the usual rules (hence he can be an Assassin at all), and his character class was probably a coincidence, or he'd have been a Saber.
 * The Hassans are the only Assassin's possibly because a 'true' Assassin would never be caught or his identity revealed. Yet, in order to be a Heroic Spirit you need an identity to be worshipped or at least known. Therefore, they Hassan clan which pretends that all their heads are the same person are the only people who can qualify. Correct me if I'm wrong, but one of the notes for True Assassin says that one of his abilities makes him quite far from a normal, traditional hero, as expected of an assassin.
 * Caster broke the rules pretty badly to be able to summon Kojiro. She holds a command seal, but as far as the Grail is concerned, Kojiro is the servant of the temple grounds.
 * I was talking about True Assassin (HF). The rules of the grail system explicitly say that Assassin must be one of the Hassan - but why the hell are they even in the Throne of Heroes that the grail hacks into in the first place?!
 * Ah...oops. Well, Hassan (the first one, at least) was a war leader and Islamic missionary, so he makes a heckuva lot more sense as a hero than, say, Medea. Since all the True Assassins are supposed to be a collective identity, I guess they're riding on his coattails, or something.
 * But going back to the original question, yes she will become a heroic spirit (I don't know much about the Realta Nua ending, so anything might happen here). Heroic Spirits are not required to have an unfilled requirement, they are just required to do great deeds and be recognized as heroes. This causes the World to recognize them as "perfect existences", and take their souls outside the cycle of reincarnation into the throne of heroes. A contract with the world is not needed.A contract with the world forms a counter guardian, which is similar to a heroic spirit, but different. Counter Guardians are part of the Counterforce of Alaya, tasked with saving Humanity from destruction. Heroic Spirits on the other hand, are more like the World going "oh wow, this thing is just so perfect, it'd be a shame to lose it to the cycle of reincarnation, so I'll just take it and put it in my Throne of Heroes where it can be perfectly preserved for all of eternity." So in this case, after Saber dies, the World still gets a Heroic Spirit in the case of King Arthur, but Alaya loses a counter guardian. Short of never dying, there is no other way for Saber to avoid becoming a Heroic Spirit. And honestly, why wouldn't she want to become a Heroic Spirit? Generally, Heroic Spirit = or is supposed to = reward. It's the Counter Guardians that get summoned to hell over and over again. Also, if you think about it, Saber already became a heroic spirit due to the nature of Akasha.
 * I thought (correct me if I'm wrong) that Word of God said that what happens to Arthur is that regardless if she gets the grail or gives up, she goes back to her body, and is sent to Avalon, where she recovers and then becomes a girl in modern Britain, until she dies, and then FINALLY she becomes a Heroic Spirit or Counter Guardian.
 * When ? Where ? If it's said outside a VN or an official source (for example, in an interview), Death of the Author might be required.

The Tohsaka are descended from Altrouge Brunestud
Crack theory, based entirely on an entry on the main Fate/Stay Night page, the fact that Sakura apparently uses shadow magic, the fact that Wallachia who Altrouge helped create used something very much like shadow magic, and the simple fact that we know so little about Altrouge.
 * OBJECTION! Sakura's shadow magic is most definitely not All There in the Manual (unless you never played either of the games, nor watched the anime).
 * There's really not any information other than passing references and statements about Altrouge, vampire reproductive capacities (a clear apprehension of the Satsuki route is that she is... well... "cold as ice" if you get the idea), or a lot of other things that would really clear things up. All together now:
 * There has only been one successful child born from a cross between a True Ancestor and a human. It's mentioned in Kagetsu Tohya, I believe where Shiki is chatting with the Crimson Moon while sleeping next to Arcueid. I was under the impression that that child was Altrouge, who would therefore not have had a child with a human to continue the whole 'only one child from that mix' thing.
 * Altrouge is supposed to be a True Ancestor/Dead Apostle mix. Whether that's confirmation or not, I'm not sure (I'll have to read that part again).
 * She is, but does that necessarily exclude the Dead Apostle from being counted as a human for purposes of genetics? There's probably no direct evidence either way possibly on purpose.
 * I don't know about being descended from Altrouge, but the game implies via Kotomine iirc that she has some vampiric background, and a human/True Ancestor cross is confirmed to have happened at least once. If she really does have vampires in her family it would more likely be from that cross than a Dead Apostle considering a Dead Apostle would turn their lover first - see Satsuki - and also probably their child. Or maybe kill the child to avoid competition. Either way, doesn't seem likely that would end up with someone who's basically a human.

Shirou isn't stupid - he's just suffering from sleep deprivation the entire game

 * His daily routine is to start training his magical talents at midnight. He takes an hour to do that, and then goes to bed. He then wakes up at 5:30. Every day. With only four and a half hours of sleep a night, no wonder he's acting dumb.
 * Well, Rule of Funny dictates that he at least has Downs Syndrome (ever read the Let's Plays of the TYPE-MOON games? Priceless commentary, it's really worth it even if you've played them already). In all seriousness, though, he does seem to have a good mixture of some Aspergers-like issue and a degree of actual insanity (think about his childhood for a minute). But yeah, this seems like a very likely thing to toss onto the pile.
 * Rule of Funny aside, it's doubtful he has a learning disability of any kind (how many high schoolers know off the top of their head Aleister Crowley's association of Baphomet with tantric magic, or that Angra Mainyu is the name of the Zoroastrian devil?). I never saw anything beyond a martyr complex, myself.
 * Actually, general consensus seems to be that he may have Aspergers - people with that tend to have vast knowledge and skills about obscure things, but suffer in other, more social areas (like how he's always so surprised at how people react to things he says, aka little social-consequence awareness).
 * Also, he was riased by a Mage. And trained hard to be one. Of course he knows about occult trivia. That said, the obsession with assigning every moderately-eccentric fictional character a disorder is getting out of hand.
 * Considering how little he actually knows about magic, I still find it pretty impressive (and it still makes me doubt the presence of a learning disability). On the other hand, I also don't think he has anything like Asperger Syndrome. He may not be the world's most social guy, but he seems generally comfortable talking to people (in other words, I'd suspect he's just occasionally socially oblivious...something I can identify with). He also doesn't really strike me as an obsessive (aside from certain situations), even with his goal of becoming a superhero. And he doesn't show any other common signs of AS that I can see...
 * If you read him as a Deadpan Snarker, he seems less oblivious. You have to admit, the reactions he gets out of people are pretty funny.

If Emiya were summoned as a Caster, instead, he'd be nearly invincible.
Exhibit A) Casters get Territory Creation, which lets the spirit create an area that enhances their magecraft. Exhibit B) Shirou was at least able to make magical wards when he was alive. Conclusion: a warded area of enhanced projection magic means any enemy coming close would be immediately open to projectile attack, any enemy surviving the onslaught would still have to face Archer in melee combat (and have to deal with his general skill and his Eye of the Mind in particular), and those who can beat him in that still get to face a souped-up Unlimited Blade Works and pursue an exciting new career as a pincushion. I'd think it would take an Assassin or someone with a Noble Phantasm equivalent to a tactical nuclear strike to get him to budge...
 * You do realise Emiya has C rank knowledge in Magic and you need A rank MGI knowledge or is it A Rank AGI?But then considering who Caster(Fate/Zero) was I guess Emiya can be a Caster.
 * That's the thing though, I would think that since he is a magus in the first place (if a narrowly focused one), he could qualify. Standard stats don't really seem to come into play when servant classes are considered (Emiya is pretty mediocre all around, except in Magic Energy and Noble Phantasm), it's more what the hero accomplished or the way they lived and fought. That also makes it kind of a stretch, but Shirou does practice what little magecraft he knows in a serious manner (and he apparently learned more by the time he became Archer, if "knowledge of orthodox magic" means what I think it does), so it still strikes me as somewhat plausible.
 * It's not really terribly important how good at magic you are. It's what you're known for and what you mostly used. For example, Rider sets up Bloodfort, which is a magic that Tohsaka thinks is incredibly skilled. Yet she's not a Caster because she herself is more attuned, for lack of a better word, to the world of beasts and fantastic races. Archer is probably incompatible with Caster as while his abilities are based off magic, what he is actually specialized at is weapon usage. Sure, he uses his Reality Marble for every weapon he uses, but once he has his weapon he does no more magic. The only other spell we see him cast apart from getting weapons afaik is a mild strengthening magic of some sort on his eyes to improve eyesight. Archer is perhaps the only class he can take as the other obvious choice, Saber, has the prerequisite of being strong against magic. He never really did have any magic resistance. He had something of an affinity to archery in life even if he didn't much care for it. It shows up in his unthinking ability at it and the way he thinks ie. the stages of projection comparing to the stages of archery.
 * The resistance to magic granted as a class ability doesn't necessarily make it prerequisite for that soul to be drawn to the class mold for the purposes of the ritual. Saber is a Saber due to her superiority in close-quarter combat, and if she were another class, she'd probably still have some magic resistance due to her artifacts, but not the added class benefit. But I agree, Archer/Emiya does tend to ranged strike-and-withdrawal weapon tactics most suited to an Archer, and would only be an Archer for the same reasons Saber would only be a Saber. Someone like Odysseus could fit either one, possibly Lancer or Berserker, and get the perks of only that class while filling that role.

In another, non-Fate/UBW/HF universe, the 5th Grail War servant spirits were summoned as different classes.
Because Zelretch told me so ('course, he also told me Shirou was a mech pilot, Sakura was obsessed with curry, and Taiga had an actual pet tiger, so...). Cuchulain is summoned as Berserker (warp spasm, for the win), because Bazett gets her wires crossed. Heracles is an Archer (Nine Lives is originally a bow, after all), because the Einzberns had a last-minute paranoia attack. Emiya is Caster (see above), and holes up in the Tohsaka mansion. Medea is an Assassin (yeah, yeah only the Hassans, I know), since Presence Concealment and Rule Breaker is a **** ing scary combination. She still tries to summon Kojirou, who ends up as Saber (not much different). Arturia winds up as a Rider, since she has the skill and has awesomely powerful Noble Phantasms. And Medusa was...Lancer. Oh, come on, she ends up with Bellerophon's bridle somehow, it's not much more of a stretch to think she winds up with Perseus' (clearly misnamed) sword!
 * Didn't Arturia say she was only summonable as a Saber class?
 * Since she's got the aforementioned Riding skill and NP, and decent speed, the only reason I could think why not might be that she doesn't have a mount. For what it's worth, I don't think Medusa could really be a Lancer either...this just in. Zelretch says Arturia has a spell that summons Sparky the Wonder Horse. I think he's full of it, but it's all I got.
 * Skill in riding is a passive bonus to Saber's, probably because they're one of the knight classes. It's like Assassin's having presence concealment or Archer's having independent action.
 * Arthuria's "mount" as Rider would obviously just be a pair of coconuts Shirou's forced to bang together.
 * ... Yes, this all sounds like a fine fanfiction. Not actually speculation about anything canon-related, but a fine fanfiction.
 * But of course!

The Ultimate Assassin would be Satsujinki.
He doesn't need to be "True". In the alternate? future where the Shikiller came down on the Dead Apostles like a unstoppable force, you can't tell me that the sheer amount of mages, Church Militant and vampires going Oh Crap doesn't generate a Legend.
 * Abilities: Strength (D), Endurance (E), Agility (A), Magical Energy (E), Luck (A), Noble Phantasm (C). Class abilities: Presence Concealment (A). Skills: Mind's Eye, Fake (A+ ), Battle Continuation (B), Mystic Eyes (A+ ), Independent Action (C). Noble Phantasm: Nanatsu Yoru, Blade of Nonexistence.
 * Problem, Nanatsu Yoru isn't even a conceptual weapon let alone a Noble Phantasm, its just a really sweet knife. Also he's not THAT agile, A is the rank given to Lancer who attacks so fast the naked eye can't even remotely keep up. He'd probably be a mid tier Assassin and a low tier combat servant, since his abilities don't really work well against beings that don't rely on pure point blank fighting like vampires tend to. A big problem with him being the "ultimate assassin" is the fact that his one hit kill move isn't any better then the other assassin's one hit kills moves against regular humans.
 * Even if there's nothing inherently special about Shiki's knife to begin with (pretty sure there's something odd about it, even if it's not on the level of a conceptual weapon), it almost certainly would be if it were associated with him (thus, the tool of a heroic spirit). As for "not that agile"...he slices and dices Arcueid into seventeen pieces in a matter of seconds, and he can Flash Step (hell, "Chokushi Nanaya" relies on it); his attack and movement speed are insane. Even before he becomes Satsujinki, when he's easily on the level of the also-A-ranked True Assassin. Beings relying on "pure point blank fighting" pretty much describes every servant except Archer and Caster, and assuming servant spirits aren't too "weird" for Shiki's eyes to read if he becomes one himself, his physical attacks are potentially anywhere from instakills to Gae Buidhe-style incapacitation (without the caveat of the wounds healing if he dies). Also, other assassins' one-hit kills don't usually have the added utility bonus of working on any physical object and even some concepts. He'd be an incredible assassin, and probably able to at least hold his own in a lot of physical combat (especially since, even if he lacks attack range, he's still incredibly tough to kill).
 * A weapon of a heroic spirit is not necessarily a Noble Phantasm, the weapon has to gain fame and have along history, it also has to possess an unusual aspect or ability. Nanatsu Yoru has none of these things, it would in fact just be considered a weapon like Monohishozo, Dark, Rider's Nail, and the Axe Sword. Nanatsu Yoru would most likely chip and break if it were to clash with a holy sword/demonic sword. The funny thing about Shiki Tohno/Satsujinki being the "ultimate assassin" is your pushing the wrong Shiki for it. Shiki Ryougi is probably a better fit, especially since she could possibly fit as a Saber depending on whether her sword is actually a conceptual weapon or not.
 * Monohoshizao is a noble phantasm. It was the catalyst Caster used to summon Assassin. The caveat was that the sword's actual wielder wasn't a heroic spirit, so the Grail summoned a random, nameless guy who kinda/sorta fit the legend behind the weapon (who was technically only a Wielder of the sword, rather than a User; hence his ??? ranking in Noble Phantasm). Its only special property was being absurdly long (and shows what would happen if Shiki were stupid enough to try blocking a sword with his knife...besides death by idiocy), meaning it is possible for a weapon to become a noble phantasm through fame alone, rather than special ability. This was also the case with the Houtengeki halberd...unless Fate Extra counts as canon enough to retcon that (the Fate/Stay Night description says it was the only halberd to become an NP, because it was used by a famous general; Fate/Extra says it was powered by the God of War and given to ). If Satsujinki became famous enough to become an Assassin, his antique, signature knife would undoubtedly go along for the ride (though probably D-ranked; its special property seems to be not requiring maintenance or sharpening). But no, Satsujinki still counts far more. Shiki Ryougi's not an assassin, let alone an Assassin; she's a Determinating Knife Nut (secretly a Master Swordsman), more of a hunter (or Saber). Stealth was never the Ryougis' game, the way it was with the Nanaya. She wouldn't have handled the events of Prelude the way Satsujinki did...i.e. sneak through his entire heavily-warded and guarded castle entirely undetected (by the vampires and the magi assault force outside) and One-Hit Kill a newly-promoted Dead Apostle Ancestor so silently Louvre didn't even realize he'd been killed before death took him.
 * Let me put it this way, how does Shiki defeat ANY of the other servants in an open fight? Vampire's big thing is they're near immortality and the fact that they are incredibly hard to kill. Shiki IS the perfect assassin against them, as he's agile, quick, quiet, has very little prana for them to sense, and can kill ANYTHING with a single stab if hes given a second to gain an understanding of it. He's basically a glass cannon fighting mighty glaciers. The problem is, while servants do have healing magic thats not really meant to help them win a fight but just to help restore them after a fight, they themselves are also glass cannons...its just they're cannons are bigger then a knife. In short how does Shiki defeat Berserker/heroic spirit Heracles? Berserker moves at 50-60km per hour, swings a sword the size of a person so fast it can break the sound barrier, and his point of death is probably a foot taller then Shiki is. Shiki runs into the same problem with basically every single servant. Mind you, he'd be absolute death to every master...if he could get close to them, but as you yourself pointed out, he wouldn't be a true assassin, and wouldn't get the proper presence concealment bonus that True Assassin has, so he probably wouldn't be able to slip by servants.
 * He doesn't defeat any of the other servants in an open fight (except a Caster; they're very much like typical vampires or the more normal Dead Apostle Ancestors like Louvre). He's an Assassin, not a Saber; even aside from relying on, you know, assassination over dueling, they're explicitly stated to be much more likely to go after Masters. Hence, he defeats Berserker by killing Ilya (Berserker's a terrible example, anyway, Type-Moon Complex aside; no one beats non-Dark Heracles in a straight-up fight without a trump card like Caliburn, and even Gilgamesh resorted to Enkidu). Even True Assassin didn't win any fight against a servant without driving them into the shadow first (he trapped Lancer and Saber that way, got his ass kicked by Rider and Archer, and killed Kuzuki without bothering to fight Caster). Even then, Satsujinki would still have a very mildly easier time of fighting Berserker than Hassan; entities can have more than one point of death, their location is more-or-less random (facing a few giant monsters didn't stop Shiki in his fight against Nero), and "healing magic" is explicitly meaningless; God Hand is no more invulnerable than Ciel's immortality, and the mystic eyes got around that easily (the "deathlessness" of servants having already been addressed). Also, I didn't say anything about Satsujinki not being a true assassin, just not a True Assassin (after all, even Heracles can supposedly be an Assassin; he's only barred from Caster). The special parameters of the classes aren't exclusive to those classes; Medusa has Independent Action, Arturia has Riding, and even Kojiro has Presence Concealment. Satsujinki already has Presence Concealment, regardless of him getting the True Assassin boost.
 * Looking at the qualifications for being a specific class of Servant Satsujinki could also qualify being a Rider, and a Beserker. He'd qualify being a Rider because they are considered to be close combat Speed Bruisers or Fragile Speedsters compared to other classes which any Shiki definantly is and also Satsujinki most likely has one of Nevar's familiars permanently grafted to his body (that he could potentially control after a few years of practice) making him more affiliated with beasts, though he doesn't have any particularly powerful ability except his Mystic Eyes. He'd qualify being a Beserker because the qualifications to becoming a Beserker is that hero had to have gone beserk or completely lost it at least once in his life (and was known for doing it) so his Nanaya Mode moments for killing Acrueid and Nevar and whoever else pushing him into this Beserk state qualifies him automatically. I would've said Lancer but he doesn't use anything that remotely counts as a lance. Lastly Shiki can become a Heroic Spirit because he is unique with an exceptionally rare ability so the World won't pass over any truly recognizably heroic deeds that would qualify him in modern times because "anyone could've done that with enough practice" since his eyes are too unique to pass up.
 * Berserker, perhaps. His inversion impulse and Perfect Play AI tactics against monsters probably would count...but Rider? He doesn't have any symbolic justification for it (hell, Arturia has more justification, and she's explicitly limited to Saber). The thing grafted onto his body didn't have any form; the only thing suggesting it could manifest otherwise was the short story "Dawn," in which case Shiki doesn't have it any more, anyway.

The story was originally a lot more fluid
Looking at the flowchart, on Heaven's Feel, you can get Rin and Saber points, despite them having no effect on anything in that route. Obviously originally there weren't exact "routes" so to speak. Instead the story flowed depending on the choices you made, narrowing down onto a "route." Ultimately resulting in one of the endings currently in the game. (Or maybe even more, like say, for example, getting enough Saber points in HF might have given her a better ending for her...) In the actual released game, the only remaining sign of this is the one Bad Ending you can get in Fate that shifts you into Unlimited Blade Works.
 * I dunno, Tsukihime has something similar (it's possible to get Akiha points when you're firmly in the Near Side routes)...but damned if I can explain, so why not?

Saver succeeded in winning an uncorrupted Grail War
The original King Arthur, he wished for the exact same thing Saber wanted. That someone else would become King instead of him. Cue Reset Button, and Arturia pulled up Excalibur instead. Via the Butterfly of Doom, changes in this new timeline randomly lead to a group of villagers corrupting the Grail by creating a Hero that is All The Evil In The World.
 * Also a bit of You Can't Fight Fate, since Arturia went through the same final events of the legend.
 * Problem! Zoroastrianism dates back to at least the 5th century BC. Angra Mainyu lived before King Arthur was around.
 * I thought that was referring to the Einzberns summoning Angra Mainyu...though on re-read, I don't know how I got that. Or, alternately, since poor Avenger was really just named after the Zoroastrian devil, it might still work.
 * I was under the impression that he is indeed the real, actual Angra Mainyu and that those villagers were the founders of the religion. It's just that he wasn't the devil as well yet they decided he was as part of the core of their beliefs to make him the Root Of All Evil In The World! That just elevated him to an anti-Heroic Spirit, though one that has no power. However, the Butterfly of Doom theory can still possibly work if you do indeed consider that one of the reasons Saber was rebelled against was that people were secretly resentful of a girl King, which would change the war slightly. That might affect the 'future' after the war and have caused the Einzberns to summon a different spirit than Angra Mainyu such as Jesus or something. Jesus loses the Grail War because he's also not a fighter, but doesn't corrupt the Grail because he's not incredibly resentful like Angra Mainyu was and therefore leaving an uncorrupt Grail for Saver to use. HOWEVER... uh, Servants can't actually use the Grail, remember? When they touch it, it absorbs them and turns their souls into pure magical energy for fuel as a wish to reach Akasha, the origin.
 * Darn you, Nasuverse continuity. Isn't the chance to get a wish the whole reason Servants are fighting at all? I was under the impression that last Servant to survive was able to do so, if they could slip the Command Seal of their Master.
 * How many actually had a wish? Saber, True Assassin, Caster in FZ (until he decided his wish already came true) Caster Caster if she didn't decide while dying that she didn't need it... A lot of them actually explicitly state that they don't care about it, like Rider (Fate Zero), both Lancers, both Archers, Assassin. One Berserker obviously didn't care, the other wanted to protect Ilya, Rider in FSN was protecting Sakura... The Magi are wrong, the Servants seem to want to hang out a lot more than they actually care about living again or anything. Lancer even says specifically says that a real hero is satisfied with their life and would not care about fixing anything or living again.

Avalon is the true Holy Grail or else it becomes it; and is the source of the legend.
No, not the Ritual Mage Cup of Wishes that was created in the 18th century, but a source of Life; of Healing; and the path to Heaven if one "strives forever." Not a cup, and not a cauldron; but a container nonetheless.
 * It's even in the name. "The ever distant Utopia." Kotomine even comments this was the original name of the Pot of legend; that the magecraft just attempted to copy the effect. The Realta Nua ending of Fate has this far older miracle triggering.
 * It should be noted, that while Gilgamesh has the originals of all magic weapons, he does not have an Avalon equivalent. This implies Avalon's existence is separate from Excalibur/Calahdbog/etc.
 * Saber wished for the Holy Grail. If she had it, she wouldn't have offered a Counter Guardian contract. She may have lost Avalon, but she did not consider it the Grail as she was already looking for it before everything went to hell. Therefore, there's a Grail that existed prior to Avalon. However, it's noted that there have been hundred of Grails documented. Avalon may be counted as one based on its properties, but it wouldn't be the original.
 * Frankly, it always struck me that the World was being a Jackass Genie here. It sent her twice to a copy Grail created by mages a thousand years in the future that was so corrupted it wouldn't do what she wanted anyways. The Literal Genie would be that they at least called it "The Holy Grail." The reason Avalon didn't trigger the wish conditions is because nobody called it "The Holy Grail." Extra Irony points for God Was My Co-Pilot.
 * This raises the question, though, where Arturia heard that the Holy Grail granted wishes. Even in Arturian Legend it didn't do this.

Shirou is an RPG player
Saber says the Status Screen is shown on the way most fit to the Master. Shirou's Status Screen has Alignments, Atributes, level of the atributes in a bar clearly showing points for them, and no one but him knows what that max base damage of Gilgamesh's main attack as "4000" means... That's ignoring his view of magical capacity as MP points, with a precise number of points used and recovered. Saber usually has a completelly diferent metaphor for them, but when applied to Shirou's terms (her words) she addopts the same MP counting. Really, Shirou makes FSN look like a GURPS adventure or a FF with only scripted battles.
 * Considering it's Rin who gives him that book, we can speculate that she's a closeted RPG nerd herself...
 * In other routes, though, Saber's the one that gives Shirou the status screen, and it still looks the same. Definitely Shirou.

Saber, Iskander, and Gilgamesh were the Biblical Magi
Because they are three Kings. "Three Kings", get it?..
 * Does that mean Ilya is Jesus?
 * ... if so, then going to church on Sundays just became simultaneously awesome and horrifying.
 * It makes sense, if you think about it.
 * So would that mean that Kotomine is actually Vatican and Sakura is the Anti-Christ?
 * Shirou is the Vatican. Kotomine is Satan.
 * Berserker is the Vatican. Shirou is Jesus' Onii-chan.
 * Shirou seem to be more of Mary Magdalene; though the idea of Onii-chan is not without merit, one could argue of Otouto-chan. Kiritsugu and Irisviel are Joseph and Mary respectively.
 * Irisviel makes a fine Mary.
 * Nice job, guys... don't mind the grey matter and blood on the walls.

Saber Lily is an echo of an Arturia whose gender was accepted by the Britons
Clearly, that outfit is not trying to disguise her gender. In some Alternate Universe; Arturia was a full-fledged Lady of War. This lead to events changing so that Arturia didn't lose Caliburn. For some reason, Saber can access this self in Unlimited Codes although her memories are still of this universe
 * I Knew It. "Saber Lily is a what-if version of Saber, passively made pseudocanon by Nasu with a Hand Wave, saying she's a "refraction of the Kaleidoscope". In other words, she's not going to be in any real story. She's Saber if she took Caliburn but chose to take the title "Queen Arturia" and force the peasants to accept a female leader instead of becoming King Arthur. She never loses Caliburn but never acquires Excalibur, though she does receive Avalon from the Lady of the Lake. She was created by Takeuchi (Type-Moon's artist) making sketches of characters in alternate clothing, and falling in love with her design."
 * Darn it. I was going to say that one! Or rather, that Saber Lily was a younger version of Saber. The outfit definitely makes her look as such.

Archer was married to Rin in his original life.
And she's the one who eventually killed him, or caused his death. Archer made a contract with the world to save a "mere hundred people", and the person who eventually betrayed him was one of that number. The flashbacks is very vague about the person who betrayed Archer, however it is clear that not everybody agreed with his actions and ideals; some thought him to be cold and mentally unstable. After hooking up with Rin after his version of the Fifth Holy Grail War, his heroic nature resulted in an eventual enstrangement with his more thoughtful wife, who thought his actions caused more harm than good. Eventually, the pragmatic Rin decided that a dead Archer was better than a live one, and, knowing his weaknesses arranged for him to enter an inescapable battle. Archer does not hold this against her; he loved that pragmatic side of her and understood why she thought this to be the best course of action. This does not mean he's going to stop making fun of her younger self, however.
 * The one who killed Archer was one of the hundred he saved who would later use him as a political scapegoat and have him executed for so called "war crimes".
 * And considering Archer explicitly believes that Rin can keep a rein on the determinedly idealistic Shirou in UBW, not to mention that Rin is much, much less of a pragmatist than she herself believes, this doesn't make much sense.
 * What? No it's possible that he was married to Rin, but not for the reasons above, as that story doesn't exactly make sense. Honestly, Archer's life is pretty vague.
 * One of Archers shared dreams actually reveals he had a lover, pretty sure that means he wasn't married.

Saber is Really Lawful Evil by D&D standards in spite of what the info screens say
"More valid for Bo ED than Bo VD - given the long list of evil actions, and "evil for a good cause is still evil" it's quite easy for a character who would be an antihero elsewhere, to be Evil by BOVD/Champions of Ruin rules."

Given the following quote, apparently from the D&D Book of Vile Deeds, Saber is Lawful Evil. She committed the "evil" act of looting her own towns for supplies, thus dooming the residents. However, it allowed her to mobilize her army to protect against imminent invasion and in the end, she saved many more towns than she would have been able to otherwise. That doesn't matter though, because "evil for a good cause is still evil", so her evil actions supersede her intelligent planning and good intentions. Thus, in addition to Saber being Lawful Evil, we can also conclude that Stupid Good is the only true good alignment in D&D.
 * That just meant she was committing evil acts, not that she herself was evil. If she believed that sacrificing people to save even more people was not her best option, but her single viable option, she herself can still be considered Good-aligned. And considering her angst over her kingship leads to her wanting to erase everything she did as king, we can conclude that she really wasn't thrilled with what she was doing. Besides, even in D&D, there's a difference between a Good/Evil act and a justified act.
 * It wasn't her single viable option. It was her best option because it saved the most lives. She could've done like her knights wanted and not looted her own villages, and in doing so let some of her other villages be destroyed by the invading army. The game goes into great detail about how Saber was hated because she made the hard decisions that were in the country's best interest, even if they presented a moral ambiguity. Her knights would've rather let the villages be destroyed by the enemy army because that way they could pretend it wasn't their fault. Saber, on the other hand, made whatever decision saved the most lives, even if it involved her taking some.
 * Thanks to the poorly implimented Alignment Modification System in D&D with many GM's out there who don't put Plot over Mechanics, she could've burnt england to the ground and killed everyone living there, and then found a temple to donate gold at and been 100% Chaotic Good.

The True Ends of Heaven's Feel and Unlimited Blade Works are the only routes with true sequel hooks.
In UBW True End, Rin and Shirou are both going to England. Do you know where King Arthur Arturia is supposed to be resting until his her return?

Also, HF True End is the only ending where we don't find out the conclusion of Shirou's character development from his perspective, and has things like Rin dealing with her conflicting feelings for Shiro, and musings on the nature of the Second and Third Sorceries that they now have experience in.
 * No argument on Rin and Shirou going to England (in fact, isn't there a sidestory about Shirou in England helping Luviagelita with something?), or Rin and Shirou's possible experiments with Kaleidoscope and Heaven's Feel...but as a minor nitpick, Arturia is supposed to be resting in Avalon, not England. In fact, that's what makes it possible for the Fate True Ending to have an actual sort-of sequel (Realta Nua Last Episode).
 * HF does give the best sequel hook/most room for expansion, but it also dropped a rather inglorious bridge on Saber. Dying in battle or dying at the end is okay, it's not necessary that she lives. Turning evil and being forgotten is probably not. Also, to judge by FHA, they decided to hell with going by any specific ending and took a third option. No need to tie themselves down so strictly.
 * There's a way to bring back Saber for a sequel too! Remember, Saber's actually alive, even if she's manifested as a half-spirit, so The Corruption of Angra Manyu might have infested her actual self. Shirou killed her without removing The Corruption, so since the deal failed, she could have been sent back in time completely evilified. So, in a hypothetical sequel, evil King Arthuria could be a villain! And then Shirou must try and use Avalon to free her. Dramatic conflict, important moral choices, unresolved sexual tension, ba-da-bump-tish.

A Future Grail War wiil cause the Great War.
Yeah, it's a bit of a stretch, but work with me here. The Enclave, wanting to get Armageddon over and done with so they can proceed with the Vault experiments somehow managed to find out about the Fuyuki Grail War and the destructive consequences of the the 3rd & 4th one. They then managed to manipulate the Magic Association into reinstating the Grail War and have the battles start anew. On the the final day of the War (October 23, 2077) the winner makes their wish on the Grail, which will wipe Fuyuki off the map. The Chinese, thinking the U.S. started a preemptive strike, drop their bombs. the U.S., thinking the same drop theirs. The rest, as they say, is history.
 * Why would the Chinese think the U.S. attacked Japan?
 * It sort of makes sense, who else has the nukes and would be willing to 'casually' fire one at Japan. Not saying America is trigger-happy, but they do have a lot of nukes. Not to mention since the 'nuke' was pretty much untracable, who has the technology to do that?
 * And to answer the previous question, because the U.S. in the Fallout universe became isolationist and extremely paranoid. A preemptive strike on country close to China wouldn't be that hard.
 * I've never played the Fallout games, but do communications really suck that badly there? Or did Japan suddenly become a worldwide military power? It seems like a huge stretch for an unrelated country to assume that an isolationist power would randomly attack a completely random city in a non-threatening country (with an undetected attack that doesn't resemble a nuclear blast) and resort to nuclear war. At least, not without a "What the hell, man?!" phone call first. (Not touching the feasibility of a sixth Grail War; this is WMG, after all)
 * In the Fallout universe, the US invades and conquers Canada.

Shirou will eventually lead a Five Man team of Justice.
All of the following is based on Rin's idea for a magic tournament involving her, Sakura, and Shirou. After the events of HF, Shirou will eventually master his art in Gradation Air and be able to manifest UBW. Despite abandoning his ideal of a superhero, he'll still want to help others and the easiest way is to use his superpower. Rin backs him up with her knowledge and command of the Second Magic. Sakura becomes the chick with an unlimited supply of Prana and technical control over the Third Magic. Fate, or Nasu, eventually tells us who has the Fourth Magic and that person joins. They eventually meet up with Miss Blue, the freelancer who also joins up because their goals coincide, or rather she was just bored and they seemed very funny. Incidentally, she also becomes the lancer.
 * They get really tacky and colorful names like:
 * Rin: Justice Red
 * Sakura: Justice Violet
 * Aozaki: Justice Blue
 * Shirou: Justice...sword?
 * Honestly, I'd expect Sakura to be The Lancer and Aoko to be The Big Guy...

Had Avalon not been in his body, Shirou would still have summoned a Saber-class Servant if he consciously tried
Judging by his reaction to The Reveal Flash Back of Saber's true identity, he apparently has a sword fetish.

"Shirou: "I also thought Lancer's lance was beautiful when I saw it, but my interest in swords is exceptional. It seems Emiya Shirou is easily attracted to swords.""

That said, combined with the fact that when lacking a catalyst, you summon a servant with a similar personality, that would at the very least make it possible for him to summon an Idiot Hero. Or, maybe a hero with a sword fetish. Of the former, I'm thinking Arthur just for laughs, seeing as he's technically the same person as Saber, only not exactly? Conjures up a very bad mental image for what happens when the guy runs out of mana, though...
 * Of course Shirou has a sword fetish. His body is made of swords.
 * Especially since in UBW, he spends a good chunk of his time openly pining for and lusting after Kanshou and Bakuya. "If I had his swords..." becomes like a broken record.

In all three routes, Archer's plan worked.
The expected effect just happened a bit slower than usual. The sharing of experience that results from the meeting of the selves resulted in knowledge being planted in Shirou that he simply should not have, causing the contradiction in Gaia that Archer wished for. After the endings of all three routes, Emiya Shirou eventually fades away and disappears, leaving behind neither trace nor memory of his existence. He lasts longest in Fate, but he still pops out of existence due to the nuggets of Projection knowledge he absorbed from Archer before he died. In Unlimited Blade Works, the paradox of a Reality Marble being manifested before the appropriate procedures are processed results in Shirou's thread of life being unravelled by the World when he attempts to manifest his Reality Marble after his climactic confrontation with Gilgamesh. Heaven's Feel Shirou, despite having a large buffer due to his nature, still has had the most paradoxical future knowledge implanted directly into him, and dissipates three years after the Grail War, after Tohsaka cajoles him into using Archer's knowledge of projection. Archer does not get what he wanted, since his existence is maintained outside the three timelines, but his presence results in one new combined timeline, the common factor of which is Shirou's non-existence, thereby making Fate Stay Night utterly pointless.
 * In the new timeline, Supervisor Rin, (aided by a gloating Kotomine) manages to retrieve Avalon from a dying, pathetic rogue magus Kiritsugi, (who has adopted no one and dies unhappy.) She then uses it to summon Saber. Sakura remains the compliant sex-toy/doll of the Matous, and enters the War with her Rider, killing Shinji before the War proper begins. The Shadow manifests due to Sakura's resentment of Rin, and Zouken happily decides to make her his new body. Zouken summons True Assassin, and, with Rider's assistance, slays Caster, her fictional Archer, Lancer and Kuzuki. However, his attempt to absorb the disobedient Saber who has assaulted the mountain against orders is foiled when the Shadow decides that the newly-arrived master Rin is the more important target. Saber, freed from the grasp of the Shadow, counters Zabiyana, slays True Assassin and rescues Rin, though the release of Excalibur required for this destroys most of the Ryudou Temple and obliterates Zouken. Eventually, Gilgamesh and Saber are swallowed by the Shadow, after both were weakened by their mutual battle, and Rin is forced into an alliance with Kotomine, who had earlier killed Ilyasviel after Gilgamesh slew Berserker. However, this is merely sport for Kotomine, who knows that he is merely sending Rin to be absorbed for abuse by Dark Sakura. Then... the world ends as Angra Manyu is summoned, and Kotomine gets his answer. Poof.
 * ...doesn't the existence of the Second Magic (or hell, the very nature of the Nasuverse) contradict all of this? Or at least the existence of Fate/Hollow Ataraxia and Realta Nua: Last Episode? The fact that there are three timelines to begin with (none of which are Archer's) means that a paradox is flat-out impossible. Also, what's so paradoxical about Shirou's UBW? He specifically points out in the incantation that the reason he can do it is because he's faced the embodiment of his future ("Withstood pain to create weapons, waiting for one's arrival") and firmly rejected hopelessness while embracing his ideals ("I have no regrets, this is the only path"). Sounds like a pretty good prelude to projecting your soul on the surrounding area...
 * This was supposed to go into Poison Oak Epileptic Trees. I'm not sure how it got here... I blame too many tabs.

In Heaven's Feel, the focus of Shirou's Reality Marble has shifted:
Since Shirou's internal world is now different enough from Archer's that he is unable to project his own Marble, despite UBW Shirou being able to reproduce it after analyzing its structure once, the properties of his Marble might be very different now. Let's have your ideas as to how; here's mine.
 * From production to analysis - Since Shirou has decided to reject his ideals for selfish reasons, his ability to use his internal world for material projection has decreased. In return, however, his ability to analyze and record weaponry has amplified due to Shirou's greater understanding of his motivations and true nature. This allows him to perfectly project and reproduce technique without losing ranks due to imperfect analysis. However, the lack of materials provided by the Marble prevent him from making dozens of swords consecutively in one stroke like Archer can, and causes greater strain on his body as he has to provide the mana for construction each time he produces a Noble Phantasm.
 * I think this is pretty much right. In UBW, Shirou lacks pride in himself, so he can easily channel the experiences of lots of different heroes. In HF, he's regained a sense of pride, so while he cannot project en masse, he has a better sense of sympathy with what he's projecting, allowing perfect projection. Indeed, even projection that is to some extent better than the original, but instead representing the best of what the original can accomplish. Hence Nine Bullet Revolver, and defeating Black Saber with just Archer's twin swords.

The Realta Nua ending is the true ending.
Merlin says Shinou and Saber can be together if she waits for him forever and he runs after her forever. Since she's in a paradise outside of time, she can potentially wait for him forever. Since he's a Counter-Guardian, he can run after her anywhere in time and potentially in all times.

Of course this cops out on the statements made in each of the endings. Imo it's more likely Type-Moon threw it in to dry fans' tears with a puffy-cloud fantasy.
 * Saber did not have her contract fulfilled, so she's not a counter guardian. But still, KING ARTHUR, and there's no way she can get out of being a Heroic Spirit. So she's still stuck in the same place Archer is, but neither are really 'conscious' when they are there. And it's outside time so they're presumably always together there, just never, you know, aware at all. So technically you could say they're together. In the sense they're both located there. But not emotionally or intellectually. Also, even if she's in Avalon instead of Akasha (which I doubt) there remains the fact that Archer has no free will in his normal range of duty, and the Grail thing has been stopped. For them to be together would require someone to summon a Heroic Spirit without the aid of the Grail and be able to maintain it while still allowing Archer to do as he pleases. Then he has to accomplish actual Magic (nice capital M there and whatnot) to get to the Root... Yeah, that's just a bit too long distance of a relationship.
 * Well, if he does have to search forever for it. That should give him plenty of time to figure out a way, even if it's just Alaya finally saying "Stop whining, already! You know what, fine! LEAVE!"
 * Alaya isn't sentient. Probably. And he can't retain memories, so he can't figure out a way either. Subjectively he doesn't have forever, he has 'this instant,' 'never' and 'already had infinite time.'
 * The Alaya thing was a joke. And while Archer doesn't retain true memories, he retains experiences (hence how he knows he's been summoned countless times, and that his ideal is a farce), so he really only needs the memory of his life. ...why are we talking about Archer, again?
 * Cause the Avalon ending Shirou is Archer.
 * Seriously?? That sounds...pretty unlikely. Is that actually in the ending?
 * I checked just now, and my memory was a bit off; it's not like Archer shows up onscreen or anything like that. We do see his geared Unlimited Blade Works, and Saber lamenting the changes he goes through as he pursues his ideal and turns his mind into steel. It's basically what Archer went through. I suppose you could say that it's just a Shirou who happened to have an extremely similar life and worldview. Well, the voice is still Noriaka Sugiyama's, anyway.
 * The Unlimited Blade Works in Realta Nua final episode is pretty much the half way point between Archer's Blade works and Shirou's Blade works. If you pay attention you'll notice the gears come no where near the ground, whereas Archer's gears dominate the horizon and basically descend to the ground, theres also smoke covering the sky and distance, whereas its pretty clear besides a bit of smoke in final episode. Also...Fate Saber doesn't know Archer=Shirou, and Archer won't remember what happened. Also one final line that kinda just outright murders this silly theory. "If you want to meet again as NORMAL people". The whole point of her having to sleep for 1,5000+ years was so they could meet while they were both still human.
 * Word of God says Archer went through the Ilya route.
 * No, it doesn't. Archer was close to Ilya, but only in the same way as post-Fate Shirou is, and Ilya is doomed to die a year or so after the war (Zouken says so in HF).
 * Fate/Unlimited codes version of Shirou actually seems like the best guess for which Shirou became Archer, its basically the fate route except Shirou does not fall in love with Saber, and actually comes away from the Grail War MORE determined to uphold his ideal.

There was a good reason for Assassin's Neutral Evil alignment.
Considering the fact he does help Caster knowing full well her intentions. Yet notice when Saber fights him the second time he lets the others go past him. Trying to get his master to die to atone for sins? No, he just got what he wanted from her (a good fight) and considered her now uselesss.
 * He talks back to her and she makes his ribs explode. He never considered her useful. And yes, he's a Blood Knight, but that does not really make him evil. That makes him neutral, probably True Neutral as he doesn't care about anything except a good fight. The one with a strange affinity (apart from Gilgamesh, of course) would probably be Rider. At points she's your ally. But never when you have a goal that isn't saving Sakura, no matter the cost.
 * As far as Rider goes, it could be that the allignment is based upon when they were first summoned. So when Rider was summoned by Sakura, she was fine and dandy. Then she got stuck with Shinji... And since he was never her 'true' master they didn't change the allignment.
 * The servant's alignment has nothing to do with the master's. Rider never does anything evil of her own free will, and acts against Sakura when she turns evil (although, admittedly, only for Sakura's benefit). She's Chaotic Good in the same way that Shirou is at the end of HF. She puts Sakura first, yeah, but she still doesn't like harming other people (particularly those who are close to Sakura).
 * Chaotic Good is not 'To hell with the world as long as my Master is okay.' She's more like an awesome Poisonous Friend than anything resembling 'good.' And she sure doesn't seem to mind her rather vampiric actions. Drinking blood is not a good thing in the nasuverse. Anything she does for Shinji doesn't really count, so she's not really Evil either.

The Holy Grail is actually a Philosopher's Stone.
Taking into account that it originally belonged to the Einzberns who excelled in making homunculi, this isn't a far cry. Also, the Holy Grail works by "taking souls to achieve a miracle." It's stated, or at least implied, that the Grail acts as a converter to change the souls of the Servants into a usable format...

The Emiya gland is even more powerful than the Tohno gland, and gets stronger with age.
By Hollow Ataraxia, Shirou has Saber, Rin, Sakura, and  in love with him, with Ilya, Mitsuzuri, Taiga, Luvia, Kane, Yukika, and Issei showing interest in some way or another. Caren and Bazett might also count, depending on if you consider the protagonist of HA both Shirou and Avenger. As Archer, he gets all three of those track team girls, including Kaede, swooning over him at their first meeting. Unlike Shirou, though, Archer has also seduced most of the playing audience as well, including the men, meaning the Emiya gland works in reality even though it's a fictional character, and that's something Shiki could never hope for (well, unless he killed the barrier between reality and fiction with his knife, then who knows?).
 * Shirou

Berserker is a time lord
No, really, he has 12 regenerations.
 * So the Einzbern castle is a TARDIS?

Ea's power is explicitly to destroy the "World"
The thing is, its the "World" that is the Nasuverse, which doesn't describe a planet, such as earth, but the current state of reality. Gilgamesh claims that Ea is some sort of absolute "truth", and it is. Specifically, its purpose is the restore the world to the natural state of reality without whatever influence makes it the way it is. So, it doesn't have the ability to destroy the planet, or take on the whole world, but its anti-world in that its attack destroys reality. In other words, Ea isn't so powerful that it destroys the world, but is so powerful BECAUSE it destroys the world. It's entire purpose is to eat away at reality.

Saber could be restored to true life
Several versions of Arthurian legend say that Arthur is destined to return from Avalon in Messianic style to lead Britain in a time of great need. Not all of them say this, but heroic spirits, as we know, have existences comprised of both truth and myth, and any one myth saying this should be enough to include it in Arturia's legend. Saber effectively has a "get out of death free" card in her deck just waiting for a sequel to come along and make use of it.

Shirou will eventually join Atlas
Atlas is focused on alchemy and understanding of materials, as well as on in-depth analysis using the human brain. Since Shirou's talents are focused on analysis, and he is intelligent enough to have a B Rank True Mind's Eye, he will eventually join the alchemists' enforcers as their talents and his happen to match up. Of course, their goals will eventually contradict, but in the process he will learn enough mental tricks to make his combat analysis even better than it currently is.
 * Shirou's magic is a heretical and if the Mage's Association ever figured out he was using a realty marble they'd either lock him away for study or kill him out right. The only reason he'd ever consider joining the Association was to stay near Rin.
 * Atlas is not the Mage's Association.

Gilgamesh is actually the good guy
No, really. By harnessing the grail's soul-containing abilities, he can take over the world without (technically) killing anybody. Then, once the world is taken over, he will have enough power to use EA at its full potential, and destroy the crapsack reincarnation/counter guardian setup, with the side effect of undoing the rest of history back to the beginning of the first grail war. Without the greatest souls being removed from the cycle of rebirth, the Nasuverse stops getting less magical over time, and everyone ends up happy.
 * Um, did you miss the line where he proclaims his desire to use the grail to kill 5.6 billion people, so that only the strongest would remain to be ruled by him?
 * It's not like they'd stay dead. There's a reincarnation setup going on, and the grail mud appears to do some sort of personality archiving of its own. Gilgamesh is just trying to gattai all the souls in the world to return them to their original awesomeness.

The manga is actually being written by the characters themselves
Think about it. Sakura didn't get raped. Shinji pulled a Heel Face Turn. There's enough 'Unlimited Blade Works' in the plot that Saber could get to stay in the present world, and enough 'Fate' in the plot that Ilya might get to survive to the end. The cast are clearly writing this themselves in order to get the closest thing to a truly happy ending they've ever seen.
 * If only Rider survived it could end up being the Fate/Hollow timeline.

Someday soon, a game will be released where Alaya, Gaia, the Root, and all of those other supreme forces are revealed to be female.
And some unlucky sap is going to be the target of their affections.
 * Naturally, this person will be some future variant of Shirou/Archer.
 * Hey, don't leave Shiki out either.
 * No need of a game for ; Nasu's already wrote about it, his very first, in fact..
 * That's an alternate universe though. And it's not all of them at once, so...

Archer commits mass murder elsewhere to save everyone at the end of UBW

 * Because, independant action or not, there's no way he could have pulled of all that stuff at the end without running out of mana.
 * He's a future version of Shirou. He's perfectly capable of doing the impossible.

The Einzberns had connections to the Nazi Party.

 * Where else would Ilya have gotten that Tiger Tank? Fewer than 2,000 models of it were produced during World War II (and that's taking both the Mk. I and Mk. II models combined.
 * As insane as this theory is it makes a disturbing amount of sense. The Nazi party was obsessed with Occult and Religious artifacts. The Einzberns are obsessed with gaining the Holy Grail and will do ANYTHING to get it. Interestingly enough, grail wars happen every 60 years on average + or minus 10 years, with the last one happening far faster then it should have. Time that out. 5th war: 2005-ish, 4th war: 1995-ish, 3rd war...1935-ish. Right in the Golden years of the Nazi Party.

Shirou's not native to the Fate universe

 * Instead, when Kotomine wished for a distraction, the corrupted grail created a fire *and* summoned an orphan to distract Kiritsugu for the rest of his life. Shirou is a native of the Naruto universe, and is partway through developing the Rinnegan (see his ring eyes in the UBW movie.

Shirou and Archer will cause the Nasuverse to end in a catastrophic Temporal Paradox failure.
At some point, Shirou will see Archer use a sword and copy it. Except, Archer will have gotten that sword by copying when he was still Shirou. The insuing Paradox will destroy everything.
 * And Archer rejoices as he's blinked out of existence.
 * Wouldn't that just be a Stable Time Loop?

Tweaking UBW True End results in a Perfect End

 * 1.) Wait. Okay. First and foremost, by comparing her own life to Archer's, Saber is able to come to terms with the same thing as she did in Fate. That's canon. This being such, after going back and dieing on the hill with Bedivere, she goes to Avalon. Meanwhile when Archer disappears he had just the right amount of impact on the past that he managed to Time Paradox himself out of service to Alaya. Since he managed not to kill Shirou or make him sway from his path, Archer is either rewarded with or ends up accidentally shows up in Avalon. Here he can finally be with Saber for all eternity as they fall in love again. Aw~
 * 2.) Canonically Shinji is less of a jerk after being turned into an abomination. Before Shirou leaves with Rin to the Clock Tower, Shinji gives in to his guilt and admits everything, throwing himself on Shirou's mercy. Shirou has all ready seen Rule Breaker, knows what it does, and doesn't have Rider cockblocking him at every turn anymore. He simply walks up to Sakura, Rule Breakers her and voila, her entire route accomplished in a few minutes. Naturally they take her with them, probably to the clock Tower where Rin has decent facilities to help her.
 * 3.) Zouken no longer has Servants to save him, Plot Hax Goo to swallow people up, his worm in Sakura should have been terminated with the rule breaking, and with some intel from Sakura, Zouken is pretty much up shit creek.
 * 4.) With either Waver's dismantlement of the Grail or Kiritsugu's Leyline bump, the Great Grail is destroyed and there are no more Holy Grail Wars. Well, until some other fool magi try to make another.
 * There. Shirou will be a revered hero instead of a reviled one, Rin gets a nice husband and gets to become a great magus, Sakura herself can start enjoying life, shinji is less of a jerk, the Grail is gone, Zouken is dead, Archer and Saber live happilly ever after, and Shirou gets to have foursomes with Rin, Sakura and Luvia.
 * The discussion of this has been moved to the discussion page, due to being overly long.

Shirou is Hungry
Shirou is actually hungry throughout the entirety of Fate/stay night. After all - he's a teenage boy, they eat a lot (I remember quite well when I was one), he's always running around fighting and trying to survive, plus Tracing has to burn up an assload of calories. The guy's practically starved whenever he makes love to a heroine, even when he's just eaten...
 * It explains all of the food metaphors, at any rate.

Heaven's Feel Makes You Feel Guilty For Liking the Other Women
The Heaven's Feel route is actually an attempt by Nasu to guilt-trip the players for liking the other heroines and strong-arm them into preferring Sakura.
 * "While you were off messing around with Heroine X, guess what was happening to Sakura the whole time? She was getting raped with worms. If you do not like her you are a cruel human being."
 * So what? A lot of people suffer. I still prefer Saber, thank you. At least she doesn't turn into a mass-murdering abomination...
 * No, but she *does* kill Shirou entirely of her own free will in one Bad End, and she does loyally support the "mass-murdering abomination" (even before Sakura herself is aware of it). Sakura is not in any way to blame for what happens in HF, and she deserves better than to be left to be tortured whilst her moronic sister runs off to London with the guy she loves (and the only guy she is ever happy around) without even thinking of looking to see why Sakura is only happy around Shirou. Plus, I can't think of all that many people who suffer anything like as badly as Sakura did.
 * I Find this whole thing amusing as while Heavens Feel does make you feel guilty about whats happening to Sakura it actually made me like Ilya a hell of a lot more then Sakura, whereas the whole route is literally a "what stupid thing will Sakura do next" festival, Ilya always seems to try and help Shirou even though she knows that in the end a sacrifice will be necessary between the three of them. Also considering what her life has been like (Parental abandonment, training from hell that nearly killed her, constant manipulation and borderline brainwashing, no friends besides her maids...which she made herself) she has it nearly as bad as Sakura does. Mind you I don't dislike Sakura, its just the whole route is caused by her mistakes
 * You do know, right, that Ilya knows the identity of the shadow from the very beginning, and further has magic which could quite possibly have helped Sakura? She is sure as hell not blameless. On the other hand, of the main cast Sakura is probably the least to blame for what happens in HF, because she had no control over most of it. Could you please name the mistakes that she made? Because, other than running to Zouken (which was indeed stupid, but understandable given the situation), I can't think of a single one.
 * Honestly, I don't think the reason Sakura may not be as popular as the rest is about blame. Personally, I think we have a What Measure Is a Non Badass issue here. We've seen Rin and Saber kick ass a lot, and Ilya gets points for the weird mix of cuteness and hilarious insanity she is. But Sakura's entire character is about her Woobie-ness. Personally, I think you need other aspects to make a character likeable before turning them into a Woobie. To me, Sakura felt kinda lacking in that department, and of course, that whole mess with Saber being turned evil for her didn't help, either. On that note, Saber Alter's loyalty. Dunno about that. To me, it always seemed like the corruption left her with her memories and basic personality intact, but changed her very nature. So, in other words, evil was forced into her personality. If Sakura is blameless, then Saber's only fault was not being able to avoid being sucked into the shadow.
 * Well, you're probably right about Sakura (in terms of "not being Badass enough"), but she's like that for a reason. It would not make sense, given her situation, for her to be fighting, because the worms mean that she cannot fight only for herself. If she fights, she's fighting for Zouken, with all the potential bad things that that entails, and thus it makes sense for her to reject doing so, especially with Shirou involved. Further, whilst I'd agree that she's not "Badass", she is also not defined solely by being a Woobie. She has her own personality, with her own strengths and weaknesses, just like everyone else, and she is actually a very strong girl. Plus, she shows in HF (when Rin confronts her and threatens Shirou) that she is perfectly willing to fight provided she has a cause to fight for. It's just that her lack of self-confidence, her self-loathing and the fact that she can't fight for herself without risking harming others (due to Zouken's power over her) means that she chooses not to. As for Saber, the argument you gave applies equally the other way. If Saber is blameless for what happened in HF, then so is Sakura. So, if some idiot Saber fan is going to come on and complain about Sakura turning into a "mass-murdering abomination" to try to justify not caring about her, then I don't see anything wrong with pointing out that Saber was supporting her....
 * Well, yeah, maybe that mass-murdering abomination thing was a little undiplomatic. I just felt like being blunt. Kinda like what Rin did when she wa fighting Dark Sakura with Zelretch. Then again, that got her mind raped. Anyway, it's not that I hate Sakura. I have no reason to. It's just that I didn't feel particularly affected by her plight for some reason and seeing all the trouble that she's (indirectly and blamelessly) causing kind of made me wonder if it's all worth it. Fiction is a strange thing. So is affection. One person may get attached to a certain character, another may hate them. But the general consensus depends on how the whole thing is presented. I get what they want to say, really, the poor girl, suffering so incredibly much, yet still being brave and holding out. It just somehow didn't work that well on me. Really, we could launch an endless philosophical discussion here on morality, blame, inherent evil and the right to exist, but where would that lead us? The situation in Heaven's Feel is obviously a choice between two evils, saving Sakura and letting her alter ego go on killing sprees in the meantime or putting an innocent girl down. So, seeing the consequences, there would obviously be a few people who'd instead prefer the Mind Of Steel ending. My guess for why: Time. It's just that HF is the third and last route and players already went through two routes, got to know the other heroines and experienced a lot with them. Plus, we are talking about a verse here where the Dysfunction Junction runs wild. But in Fate and UBW, Sakura barely had a role bigger than Taiga. By the point HF starts, there's a good chance most players would've already picked their favorites. Of course, obviously every route has a new heroine, but still, certain appeals will already be present. Now not only in that route do we have to "really" get to know Sakura, while Saber and Rin basically shared the last two routes equally, we also get presented with her whole tragic backstory and all. It's further "shoehorned" in when they get rid of Saber to make some extra space for Rider (who, I think, still didn't get enough screentime). So, maybe it all would have been more effective if the routes had played out differently, had given the player more time to get to learn the "normal" Sakura before coming out with her own backstory and route, to create more of a "We've been through so much, I can't let her down now!" feeling, if you get my drift. Or that's my guess what went wrong, anyhow.
 * Really, I can't imagine how Sakura's any more shoehorned into Fate/Stay Night than Kohaku was in Tsukihime. Structurally, Heaven's Feel was FSN's equivalent to the Far Side paths, the ones that deal with the story from an entirely different angle. Then again, I've gotten into enough arguments already about it to see what you mean...I still love her, though.
 * Yeah, Kohaku was kind of shoehorned in as well. If she's more popular than Sakura, that's because of how later materials mainly replaced her Woobiee-Persona with a more mad scientist-like one. So she causes hilarious insanity around the Tohno Household and that makes the fans like her. Or something like that. That said, I don't really like Kohaku. Can't forgive her for getting Akiha killed.

Rin will also become an Heroic Spirit/Counter Guardian
Self-explanatory. Rin will be recognised, in some timeline, as a being worthy of being a Heroic Spirit or making a contract with the world and becoming a Counter Guardian.

If in the future await so many tragedies as Archer says, I don't really think that Rin would just stand doing nothing. We all know she fails at being the pragmatist she wishes to be, and people suffering/dying is not something she would ignore... specially in a timeline in which she has Shirou has her lover.

Also, sorry for the pun on the title.
 * Magi hate and fear the Counter Force, though. They're the ones who tend to show up when they're not wanted and screw up your experiment to get to the Root (if I heard Touko and Souren's conversation right). I guess that doesn't totally preclude her willingly joining the Counter Force, but it would still require a non-UBW route (she knows Archer's story in that, and he admits out loud that she's smart enough to keep Shirou reined in) and for something really strange to happen to her motivation; she's not a total pragmatist like she wants to be, but neither is she the unquestioning, hardheaded idealist that Shirou, Saber, or Joan of Arc (the only Counter Guardians or equivalent we know of) were. Becoming a Heroic Spirit is right out. The last one to do that was 150-200 years ago; it's near impossible for someone in the present to do something that is literally so ungodly exceptional and awesome that the world considers them perfect enough to set aside. Rin's more likely to become the full practitioner of Kaleidoscope before that.

Archer is not from a specific timeline, his past changes as the events unfold
At the beginning where Archer cannot remember his name is due in part to his past being in a state of quantum flux. His past and subsequently his identity is altered as the events of the game run through. Archer seems to have a slightly different personality in each route, this is also explained by the recursive effect. As Archer affects the world around him, Shirou's character develops differently so the Archer that is the future result of the events as they have proceeded and most likely resolve is a different person. He regains his memories as Shirou makes choices that define him as a person so elements of his character become less likely to change. As Shirou grows as a person, Archer becomes more like that person.

The Throne of Heroes is the reason modern day people suck compared the ones of the past
On the Nasuverse, when a person dies the soul is sent back to Akasha, where it is recycled and used to make more souls. All souls are made from the same source wich mean the more people running around, the weaker the souls made are. The problem here are the Heroic Spirits, when the Hero dies, his soul is sent to the Throne and left there. The souls of heroes and heroines aren't recycled, wich mean the stuff used to theirs souls never will be used to make other souls(Gilgamesh's soul alone is as "heavy" as the souls of hundreds of thousend of souls of modern day people). The material left will keep being divided in weaker and weaker souls. Maybe that is why there aren't any Heroic Spiritsf from after the 19th century. Akasha can't efford to lose more of the soul mojo it have.

The reason Ea is so powerful is because it taps into Spiral Energy
Think about it for a moment: Everyone knows that Ea is a sword that is more or less shaped like a drill. More importantly is that, for all practical purposes, its attack has unlimited power. (When you can destroy the world with a single swing, there's very little that can stand up to you.) Also, what's Gilgamesh's plan? To use All the World's Evils to kill off the majority of humanity. He reasons that only those who could survive it would be worth ruling over. That's right. I'm saying that Gilgamesh is basically an unsympathetic Lordgenome.

Gilgamesh also qualifies for most classes
Consider it. He's an archer only because he's an arrogant (awesomely I might add) ass and just shoots his weapons like arrows. He's obviously very good at sword play (likely surpassing Arturia), so he could easily qualify for the Saber class. Likely the same could be said about the lancer class. So he at least would qualify for the 3 knight classes. Most likely beserker too.
 * Actually, no. He qualifies for the Archer class because of his combat philosophy (he likes to hold the ground and he uses his weapons as if they were easily replaceable) and not because of his arrogance. He's also not that good at sword-fighting (he only defeated Arturia because he had stronger weapons), nor is he at fighting with a lance, so he could be neither Saber nor Lancer (not to mention that his fighting style disqualifies him from getting either of those classes). Caster is also out, and the same with Assassin. The only classes (other than Archer) he might be qualified for are Rider (because of his flying machine) or Berserker (but then again, only maybe, depending on the requirements of the class).

The Shirou stemming from the Fate route will go on to become a normal Heroic Spirit, not a Counter-Guardian
Simply put, the life Shirou goes on to live following the Fate route is significantly different from Archer's in that he does not become an unknown element, saving people. Instead of hiding himself and his intentions, he proudly proclaims his ideals and seeks to teach others their merits. The reasons for this difference stem from the relationship he formed with Saber...somehow. How he takes the lessons he learned and applies them to his life isn't the point. The point is that despite his coming from a time period in which it is next to impossible to qualify as a Heroic Spirit; after a lifetime of Heroic deeds (After all, the one little snippet I know of regarding his future points to the possibility of him hunting DEAD APOSTLES) and in recognition of his Unique abilities, (Unlimited Blade Works seems like it would count, not to mention being especially unique as to how he acquired it) Emiya Shirou becomes a truly unique existence outside the wheel of reincarnation.

Rejoice.

As an added note, perhaps Realta Nua's Last Episode takes place in the area removed from space and time where heroes reside. As for how Shirou and Arturia overcame the supposedly complete isolation of Heroic Spirits in said realm, perhaps that is the miracle that they achieved, in the end.

The reason Shiro/Archer rely on Kansho and Bakuya so much...
The source of Shiro/Archer's projection is their reality marble. Even factoring in the limitations of their prana levels, the sheer number of weapons they have should leave them with plenty of options. But it makes more sense when you think about how their whole Possession Implies Mastery ability works. Shiro and Archer gain proficiency in a weapon by accessing its memories of being wielded (hitch are recreated along with the weapons' forms). But the vast majority of the weapons copied into Unlimited Blade Works come from Gilgamesh's Gate of Babylon, which contains the treasures in the state before they were wielded by anybody. In other words, the weapons that Shiro/Archer copied from this source have no memories for them to draw on in order to gain proficiency, which limits them to the comparatively small number of weapons that they gained from other sources.
 * Those blades were originally made for somebody, they weren't just chucked into the vault. They had wielders originally, not as good as heroic spirits but wielders nonetheless. I'd chalk Archer and Shirou relying on K&B so much as simple preference really.