Guilty Gear/WMG

Chipp Zanuff is Kakashi from Naruto and Smoke from Mortal Kombat.
He travels between Earthrealm, Guiltyrealm and Narutoria as realm crossing is a real part of Mortal Kombat. Alternatively all three worlds exist on the same timeline as Guilty Gear takes place a little over 100 years from the Mortal Kombat time likely based on our present. Naruto world can easily exist in the past or future. Many episodes from the original series after Sasuke went away start grabbing at old legends from the past in dire need of story material. If in the future, Guilty Gear technology is outlawed and magic plays an increasingly large role so the Naruto universe may well be the logical next step in civilization. Japan was destroyed in Guilty gear and Chipp was obsessed with becoming President. Perhaps upon achieving his ambition his goal was to turn the world into the next Japan which explains the dominant Japanese culture in Naruto. This too would justify Chipp as being a true Japanese as he would have redefined Japan in his image on a global scale.
 * He puts on a mask covering his face to hide his identity in Naruto as well as Mortal Kombat, but the spiky gray hair still shows.
 * His ninja training and identity are a permanent part of his character.
 * All three are capable of teleportation.
 * He is capable of turning invisible.
 * He recognizes his Thousand Years of Death attack when Faust uses it againt him as evidenced by his reply.
 * He can create shadow clones and taught the technique to his partner Noob.
 * He has also been witnessed performing this technique when he was maskless and thought he was alone in Guiltyrealm.
 * In Narutoria he is more than familiar with handseals and tends to favor the exact same handseal which he uses both while parrying projectiles in Mortal Kombat as well as while teleporting and Instant Killing in Guilty Gear.

"Badguy" isn't Sol's real last name.
But Sol was so destructive in his Holy Order days that his teammate/leash-holder Kliff had to reassure everybody that "we're not the bad guys". So when Sol stole the sword, he appropriated the last name as a Take That against the Holy Order.
 * It's actually mentioned in-game that Sol was human before, and that his human name was Frederick Mars (as in Freddie Mercury, from Queen).
 * Partly Jossed in Order-Sol's story. Turns out he and Kliff got on relatively well and when Sol stole Fireseal and left the Knights, Kliff didn't mind a bit (though he did point out that the other knights definitely would.)

Dizzy hatched out of an egg.
She is, chronologically, three years old as of Guilty Gear X. Being half-human and half-Gear, her Gear parent has been revealed to be Justice, but Justice was sealed away for five years, and was only released for a few minutes afterwards, at which point she (Justice) was killed "less than a year" before the events of GGX. Justice probably didn't give birth while sealed away. So, what kind of birth mechanism allows the mother to be absent? Why, hatching from an egg, of course! She must have laid the egg containing Dizzy prior to being sealed away, and perhaps also named her, given that Dizzy is still called Dizzy in the Alternate Universe in which Ky was killed, Justice was not sealed away, and Dizzy took Justice's place upon the latter's death.

Sol is Dizzy's father.
Only works if you accept the idea that Justice was still a human when she gave birth to or at least conceived Dizzy. ""I wish the three of us can talk one last time...""
 * Accent Core Plus, as well as Overture confirms that Justice was human at one point: she was turned into a Gear, like Sol, . In addition, there's also theories that Kliff is Dizzy's father. He's certainly old enough and knows Justice about as much as Sol does. Dizzy also seems to recognize him somehow.
 * If Justice was created from a human, then it's possible that after her transformation that Sol could still be the father. Dizzy's human side would be from Justice, as her egg cells would have all formed at birth (as a human) and wouldn't produce 'Gear' eggs since no more oocytogenesis will occur.
 * Or, Dizzy was frozen embryo and was made to develop hundreds of years later.
 * But Kliff's already Testament's father. Two Gear children seems a bit much. Besides, Dizzy's powerup move (where she starts flashing red and gains more strength and speed) is identical to Sol's.
 * Being a gear himself, Sol being Dizzy's father somewhat contradicts as she is Half Gear. Unless Sol/Justice was human at the time, the half-gear part throws a wrench in things. Also, in regards to Kliff, Testament was human and became a gear later, not born one.
 * Well there is a possibility that Justice was Aria...
 * Kliff is Testaments father by adoption, background information reveals Testament was orphaned in a Gear attack, and Kliff took him in. Wanting to help, Testament agreed to be turned into a gear himself but was unable to resist Justice's control
 * In Justice's story in Accent Core +, Sol suggests that the "complete" Gears were the masses of mindless ones, and that he and justice were "incomplete", IIRC. Perhaps both Sol and Justice would be considered half-gear?
 * I only remember Sol asking Justice if she thought there were no prototypes before her. She responded in a way that she seem to remember Sol's true identity.

Millia is sterile.
It's said that each person who tries to attain forbidden magic must sacrifice something. Zato-1 specifically gave up his eyesight for control over shadows, though Eddie being implanted into the ritual kinda made things worse. Millia's "important thing" according to her profile is her chastity. What if, to gain control over her hair, she gave up her reproductive organs (as in, she would be an actual representation of Anime Anatomy)? This would hold more weight if we knew what Venom gave up, if anything, for his own powers (assuming, of course, that his powers are forbidden magic).
 * Maybe his face, save one eye? We've never seen anything outside that mask...
 * Hmm...actually, you can see his face just fine during some of his jump sprites. He's quite a looker, really.
 * This Troper doesn't believe that Venom has a parasite; Eddie had a mind of his own, Millia's hair certainly seemed to be animate at least (like Spawn's cloak), but Venom isn't associated with anything similar.
 * This Troper personally believes that Millia gave up her virginity, due to her near-obsession with chastity after the fact (from her listed favorite thing to various Arcade and Story mode quotes when dealing with other female characters) and how conveniently it would tie in with the implication that she and Zato-1 were close, possibly romantically involved, before something happened to make them suddenly fall out to such an extent that they became mutual Berserk Buttons for each other. Also, Venom didn't go through the forbidden rituals like Millia or Zato did, and his powers are not tied to having a Forbidden Beast like Eddie or Angra. He wouldn't have had to give up anything as he simply wasn't involved in that whole scene.
 * Where do you people get the idea that Millia and Zato were ever in anything even resembling a romantic relationship? We know that Zato trusted Millia enough on a professional level that her betrayal led to his capture (which sparked his hatred for her). In Millia's Ending III in GGXX, she claims that he saved her, raised her, "dirtied her soul" (which this troper interprets as "probably killed her parents and definitely forced her to kill people", not "raped her or forced her to undergo a defloration ritual to gain hair-based powers she didn't even want") and loved her (in his own twisted way - his gargantuan ego probably led him to believe that the feeling was mutual). Due to Stockholm Syndrome, Millia probably did feel a strong attachment to Zato - Venom suggests that he (Venom) and Millia are Not So Different, in that they both pursue Zato even after his demise - but this hardly implies romantic or even platonic love. Finally, my guess is that Millia obsesses over (physical) chastity (or purity in general) as a means of compensating for the corruption of her soul/morals she has suffered.
 * The first track of the Night of Knives drama cd has Zato and Millia kissing and sharing a bed together. There was definitely a relationship more than platonic going on between the two of them. She still broke it off with him because he was a self-centered dick, though.

The next game in the series will be tag-team like the early King of Fighters games.
Just guessing based on the large number of teamups occurring in the good endings of AC+'s Story Mode.
 * That would be awesome, especially with team supers and I Ks. Dang, can you imagine Sol/Ky IK? Or, better yet, Chipp/Sol?
 * There was already team fighting in Guilty Gear Isuka, but it was more like SSB than anything else.

Dizzy is Ky's wife.
Though not official, there seem to be hints from the various interviews given by Ishiwatari himself that suggest this:
 * Ky's wife is known as the "Maiden of the Grove," Dizzy's stage is the grove.
 * Dr. Paradigm mentioned that the woman in Ilyria is a Gear who once had a huge bounty on her head but was supposedly killed and was also rumored to possess great powers. Basically, this was the plot of Guilty Gear X which introduced Dizzy where she served as the final boss.
 * Also, the Maiden of the Grove is called a reproduction of Justice or her back-up. So far, Dizzy is the only known daughter of Justice though her exact origins and genetic connection is unclear to this point.
 * The Materials collection book links Ky and Dizzy's relationship with a heart symbol and lists them as being deeply connected to each other.
 * Confirmed thanks to Dizzy's good ending in Accent Core Plus where she is shown to be visiting Ky periodically.
 * But...Daisuke has a statement in the Material Collection book that they were not officially or publicly married, Ky just calls her wife out of respect.
 * Yes, because calling someone your wife automatically equals marriage. They were married secretly. Deal with it.
 * Then does that mean Robo-Ky's married to every female (except for Bridget) in Guilty Gear?
 * If Ky and Dizzy were married secretly, why would they name their son "Sin" then?
 * I think another question is, "Is Dizzy Ky's wife or just his secret lover?"
 * Ky's official short story in Overture clearly states that he proposed to her, but cannot marry her because of certain issues (possibly legal, political or racial.) Instead, they "married" themselves.

That Man is actually THE That Man from Excel Saga.
After failing to control the Great Will of the Macrocosm he decided to turn his attentions to other all powerful beings and so is targeting the various uber powerful characters in the Guilty Gear world.

Bridget is an alternate-universe Hani.
They share similar traits: Childish cuteness, blond hair, about the same height, surprising acrobatic skills, and attachment to a stuffed animal (Roger in Bridget's case). They also want to prove their manliness, only this time Bridget doesn't have Tamaki to dissuade him.

That Man is The God-Emperor of Mankind.
He's very old, ridiculously powerful (Sol went full Gear the moment they start fighting in overture, and still didn't kill him), and has been manipulating events for who knows how long, up to and including creating the gears, who were likely a prototype Space Marine

Alternately, That Man is Lucifer.
Justifications (Guilty Gear side): Justifications (Shin Megami Tensei side):
 * He's not a time traveller, and has lived throughout all 150 years of the Gears' history.
 * While not a Gear, he's definitely not human.
 * He has shown himself easily able to withstand attacks from anyone in the series, even Sol summoning the full power of his Dragon Install.
 * In Overture, he's specifically noted that he can control his physical age.
 * When asking Anji Mito to join him, he asks if Anji is "willing to defy both heaven and earth."
 * When mentally addressing Sol, he says that either he or Sol must "do the work of the Devil." This could mean that That Man is being poetic or is admitting he's just a servant, but the Devil doing his own work still makes it the work of the Devil.
 * He's a schemer, but portrays himself as sympathetic or at least apologetic towards those he manipulates.
 * His cloak in Overture has writing on the fringe: "HEAVEN MADE MAN FOR ITS REASON. MEN RESPECT MEN FOR THEIR OWN SAKE." Emphasis: Reason.
 * He makes a lot of references to some greater threat or enemy that Sol and others will need to fight, which leads to:
 * Lucifer has appeared as a young man (Louis Cypher, Shin Megami Tensei II), an old man, and a young boy (Shin Megami Tensei: Nocturne).
 * Lucifer considers God "the true enemy."
 * Lucifer (through his nurse) shows sympathy for the Demi-Fiend via the tidbits of information the nurse gives to him. These tidbits also include reasons not to join him (would you sacrifice your humanity for power?), in the interests of a completely informed decision.
 * Lucifer created the Demi-Fiend as a weapon against God. Now, as any self-respecting scientist would know, only a complete idiot would lack the means to replace the test model if it were to break. The Demi-Fiend was a great success, but being the cunning planner that he is, there's no reason why he wouldn't have contingency plans elsewhere, even on another world. Even the methodology could be different, on the off-chance that it might work out better, or perhaps simply because it was an earlier attempt that hasn't proved completely useless yet. Say, instead of a single cohesive demon body fed into a human (magatama), the alternate approach could be a full cellular-level fusion (Gear cells).

That Man secretly controls the Holy Order.
Why else would I-No make you fight Order Sol?

Ky and Saber are fraternal twins.
Blonde hair, greenish blue eyes, selflessness, chivalry, the ability to rule as kings and their blue and white clothing? So many things similar that's hard to ignore. They just got separated at birth into different timelines, Saber to the past and Ky to the future. Very likely since both universes use magic.
 * Maybe they are clones. Some materials say that Saber was supposed to be male. Maybe Ky WAS the first saber or the male version of Saber was cloned from Ky but got rejected because of copyright laws.

Come the next 'official' Guilty Gear, Millia will get herself drafted to That Man's group or PWAB to stop her hair from completely taking over her
We know the next Guilty Gear is due for Play Station 3 and Xbox 360. Now consider this: In BlazBlue, Litchi Faye-Ling has followed a similar story like Millia, they're chasing some sort of dark creature which Was Once Human and related to them, even deserting their previous organization for that (Assassin Guild and Sector Seven). Now, Millia's story thus far ended with her destroying Eddie, but her hair started to become sentient and we never know what will happen to her, will she get consumed by her hair like Eddie, or resists it. On Litchi's shoes, her decision was to get some regulation of her Boundary corruption from NOL. Transferred to Millia, it's very possible that That Man would eye her and invite her to join his cause, in exchange of regulation of her hair taking over. That Man has proven himself to be quite the charismatic figure, he even got Anji Mito to join his cause, so if he does plan to get Millia to join him, it is quite possible.

If she doesn't join That Man, the PWAB (especially Crow) might be the one to enlist her services. At any rate, if Ishiwatari still wants to touch about the problem of Millia's hair getting sentient, she might not stay neutral anymore and needs to take a side.

Chipp is Dizzy's father.
They both have red eyes? Yeah, this one's crazy...
 * Yes crazy, because Testament also has red eyes, so he can also be her father then?

Funikura is a Gear who, somehow, ended in the Queen's Blade universe.
Lets's think about it: Funikura is sentient, just like Eddie in Guilty Gear, can control its human user (Nyx in Queen's Blade and Zato-1 in Guilty Gear with Eddie, and the way how they can control their users is, honestly, disgusting (Funikura tentacle-rapes Nyx, and Eddie can control Zato-1, even after his death.)
 * Eddie isn't a Gear. He's a Forbidden Beast.

Dizzy is a remnant of Justice from the Backyard.
Just like how Kadaj and his Gang are remnants of Sephiroth from the Lifestream. Look at this tidbit of facts: Given these, it's possible that Dizzy is inevitably a Justice back-up. And it's possible that she'll awake in her true nature given the time and circumstances
 * Dr. Paradigm mentioned that the Maiden of the Grove(see WMG above) is a reproduction of Justice, but in the Japanese dub, he says that she's a "backup."
 * In the official relationship chart, Dizzy's relationship with her mother is marked with a one-way arrow. Meaning, Justice may have no maternal connection to her except identical genetic traits.
 * Dizzy recognizes Justice as her "mother" even though they never met. She knows by instinct.

Guilty Gear and Assassin's Creed take place in the same universe.
Fredrick, Aria, and That Man all worked for Abstergo. How they found out about Magic? Through a Piece of Eden. The Post War Administration Bureau is likewise run by Templars. As for the Assassin's Guild? Obviously the Templars have succeeded in killing most all of the original blood-line assassins. Why else would they have this new Guild under their thumb?

Faust and Dr. Baldhead are the same person.
Every Guilty Gear fan thinks this is true though this isn't 100% official.
 * Who else has a scalpel, a paper bag on his head, nine foot tall, has crazy moves and atones for a past mistake?
 * This is not even a Wild Mass Guess because it's pure common sense...
 * Practically canon. Faust has a taunt where he whips off his paper bag and underneath, he's bald.

Only female Gears can be Command-type.
This troper just guessed based on the fact that all Command-type Gears have been all female: Justice, Dizzy and Solaria. It's possible that mitochondrial DNA (can only be passed to daughters) is responsible for their ability... whatever.

Ky and Bridget are related.
Both have blue eyes, blonde hair and some sort of connection to God. Maybe Bridget is older than he looks?

Ky is That Man.
Come on, they're not going to dangle this story thread for an entire franchise and not have him be one of the main characters.

Kliff never died, and has taken a back seat because he is That Man
both can alter their physical age, both are said to be extremely old. Kliff's 'death' may have been a ruse to hide the fact that what was actually happening was a transformation into a younger appearance, and putting on a cloak and becoming that man. the height issue is Handwaved by the fact that Kliff's younger form is much taller than his elderly form. Besides, Kliff hasn't appeared in canon since the first game...

That Man is Lord English from Homestuck
both are nigh invulnerable and that's all i got really. still, why the hell not?