Fusion Fic



A variety of Crossover fic where the characters of one or more franchises replace the established characters in yet another franchise. Usually written for the comedic value of the resulting Fish Out of Water juxtaposition, although the odd serious/dramatic effort is seen, too.

Sometimes overlaps with Meta Fic. Film Fic is a Sub-Trope, as is the Folgers Crossover. Compare the more typical Intercontinuity Crossover and "In the Style Of" for doing this without specific elements. Has no relation whatsoever to Fusion Dance or that nuclear stuff going on in the Sun's core or a custom DeLorean.

""By G'Quan, they've killed Kosh!" "You bastards!""
 * For some reason, it was very popular in the late 1990s to replace the crew of any given Starship Enterprise with the cast of Ranma ½. Inevitably, eternally-lost wanderer Ryoga would be given the post of navigator/helmsman.
 * Replacing the cast of Sailor Moon with the Ranma cast also had a brief vogue. Ranma was always cast as Sailor Moon. (Read more about this in Fuku Fic.)
 * Speaking of Star Trek, the villain of The Undiscovered Country being a fan of Shakespeare resulted in a close relative of this trope by inspiring someone to translate Hamlet into Klingon. Apparently it worked well enough that the New Frontier novels suggest that the immortal bard has quite a following in the Klingon Empire.
 * Perhaps epitomized by a piece of artwork entitled simply "Popeye the Sailor Moon". There are lots of these little horrors.
 * Kanius, formerly SSJ4Takeru, intertwines the Digimon and Dragon Ball Z into a long-running successful Fusion series called Digimon Fusion Kai. It has been previously and been simply called Digimon Fusion, or 'D-Fusion' in the past. As of 2010, it has been revived and rebranded with the 'Kai' label. It is now undergoing a revision to keep update with his other writing. It is an ambitious series and the battles scenes are deliciously well-written. Oh, and how could I forget? It has it's own page. Check it out: Digimon Fusion Kai.
 * Season 1 is done, which covered the Saiyan and Freeza arcs. As of now, Season 2 is in full gear covering adaptations for the Artificial Human and Cell arcs.
 * Tai and Matt are basically Goku and Vegeta in this series, except Tai is not as dim-witted and Matt isn't a ruthless killer (but his darker split personality just might be). For the record, no Tai and Matt don't share the same power levels as their Mega-Level partners in this newer updated version. Ha!
 * In Angus MacSpon's The Replacement Ranmas, Fusion and Meta Fic mix when the entire cast of Ranma ½ turns up missing on the first day of shooting for a new fic, and the "director" must scramble to replace them with characters from other anime series...
 * A rare commercial variant of this would be the "Amalgam Universe" jointly created by Marvel and DC, in which their two 'verses and their inhabitants were merged in a literal fusion; unlike a classic fic fusion, though, it was not so much a case of "character X takes on the role of character Y", but "Character X + Character Y -> Character Z, who partakes of both". For example Doctor Doom and Doomsday combine to form Doctor Doomsday.
 * Not to mention the two major mixes. Batman + Wolverine = Dark Claw and Captain America + Superman = Super-Solider.
 * Some characters were even fused twice. In addition to Dark Claw, there was Bruce Wayne, Agent of Shield (Bruce Wayne/Batman + Nick Fury). And Wonder Woman became both Amazon (Storm + Wonder Woman) and Diana Prince (Wonder Woman + someone who would marry Punisher and fight crime with him).
 * One from 4chan is Fear and Loathing in Ba Sing Se. Yes, Avatar and Fear and Loathing in Las Vegas.
 * Another one is Avatar and Batman, with Sokka as "Wolfbatman", and provides some truly horrifying fanart of post-Villainous Breakdown Azula as the Joker from The Dark Knight.
 * Then there's the Super Robot one that has Aang piloting Gurrang Lagann and Getter Momo with Sokka in the Wang Fightgar.
 * Hell, every other topic on /a/+ is an Alternate Universe, and plenty are bound to be fusion.
 * There is a Pirates of the Caribbean crossed with Care Bears.
 * Neon Genesis Evangelion had the intro redone with characters from Mariasama ga Miteru as seen here. Evangelion gets quite a lot of these if you bother to look, in fact.
 * Perhaps the ultimate examples are the first and second season opening animations for Kodomo no Evangelion, made by those crazy guys at Gainax themselves.
 * Children of an Elder God is Evangelion with the pseudo-Christian stuff replaced with H. P. Lovecraft, right down to Misato wearing an elder sign instead of a cross. There's also Aeon Natum Engel/Aeon Entelechy Evangelion, which places the characters and plot of Evangelion into the Cthulhu Tech setting. Not too big of a stretch, since CTech was partially based on Eva in the first place. Then it throws in F.E.A.R., and it still fits.
 * The Batman was fused with Kim Possible and Classic Cowboy makes it work beautifully. These stories are quite good.
 * Ben 10: Ultimate Alien and Hellsing have been fused. Guess who Kevin is everybody!
 * In the Swedish gaming mag Sinkadus, waaaay back, RPG writer Anders Blixt wrote a short story fusing Star Wars and The Lord of the Rings, entitled (in English translation) "Lord of the Rings part IV: A New Hope". It featured Obi-Wan Gandalf and Aragorn Solo leading a bunch of Jawas down into Mordor, eventually encountering "Darth Angmar, the right hand of Emperor Sauron himself!" Who is the daddy of one of the Jawas...
 * The game Pokethulhu, an Affectionate Parody of both Pokémon and the Cthulhu Mythos, has as its central conceit that there actually is a Pokethulhu cartoon series. In it, the characters are fusions of Pokémon characters and fictional or real people associated with the mythos: the main character is Ash Ketchum/author avatar Randolf Carter, while Team Rocket is Team Eibon, made up of Derleth (named after author/editor/fan hate object August Derleth) and Bloch (named after author Robert Bloch).
 * The fanfic Avenging fuses manga in general and Ranma ½ in particular with Marvel Comics in general and the Mighty Avengers in particular; the Avengers in this universe are based in Tokyo and made up of characters from the Ranma comics. Ranma is both Captain Japan and his spunky female sidekick, Bucky (never seen at the same place at the same time, which Bucky explains by their only having one indestructible shield between them); Akane is Thor (presumably because they both pick hammers out of empty air...); Ukyo is Hawkeye (who claims to be a man in her superhero identity but is unable to conceal her attraction to Captain Japan); Dr. Tofu and Kasumi are Giant-Man and the Wasp for no reason whatsoever; Ryoga is the Hulk (he stumbled onto the testing grounds of the Gamma Bomb when being lost as usual; there is also a giant green rampaging boar which people don't know is also Ryoga...); and Mousse is Daredevil (not normally an Avenger, but the writer couldn't resist the joke, also making Electra = Shampoo and Stick = Cologne...). The writing is less funny than it sounds, the main attraction being trying to figure out who is going to be who, so to speak.
 * The Wheel of Time and Transformers have had their characters fused by Rule of Funny into Trans-WoT-ers, resulting in transforming Asha'bots, Darkfriendicons, and Egwene al'Bumblebitch, with some random lesbianism thrown in.
 * Mercedes Lackey wrote the short story "Moving Targets", which is a fusion of Valdemar and, oddly, Scooby Doo. It has four Herald trainees and a kyree in a green flower-painted wagon solving a Scooby-Doo Hoax. It even includes the line "And I would have gotten away with it, too, if it hadn't been for you meddling Heralds."
 * There are pages depicting a fusion between Persona 4 and Yotsubato, with Nanako taking Yotsuba's place. It was about as adorable as you'd expect.
 * Unsurprisingly, there's a Soul Eater/Naruto fusion fic out there. The fic in question is Master and Weapon. Despite what you'd expect, the Black*Star substitute isn't Naruto.
 * The Fanfic Martian Manhunter is an interesting case. No characters are replaced; rather, Veronica Mars, along with her backstory and supporting cast, are shoehorned into the background of Buffy the Vampire Slayer's Sunnydale...
 * Hamlet played by Slayers characters anyone? Too bad it's a Dead Fic.
 * Another rather odd variation was a Ranma ½ + Star Wars fusion where, while the Nerima Wrecking Crew were all cast into roles similar to the characters in A New Hope, they didn't replace them at all! They just happened to have similar adventures before, alongside, and occasionally intersecting them. For example, Kasumi (Luke's neighbor) and Nodoka (Obi-Wan's Ex-wife) getting on the Death Star by requesting a tour, and in the process get their pictures taken with two stormtroopers (one a little short) escorting their Wookiee "prisoner". Sadly, it died before they could get to The Empire Strikes Back.
 * A straighter example of the same combination can be seen in Blade and Epsilon's Ran Wars.
 * Almost everything in the "Cartoon Crossover" section of Fanfiction.net is a Fusion Fic. I believe they call them "parodies".
 * There was once a very detailed Ranma and Naruto fusion summary, leaving a very large portion of both continuities intact. The author wouldn't use it because of the latter manga's obscene length.
 * There is a Fusion Fic for X 1999 and Chobits. It was surprisingly well-written and well-handled.
 * ... Tsubasa Reservoir Chronicle?
 * Quite a few people have read the script of the Ring Wars Trilogy (The Fellowship of the Hope, The Two Towers Strike Back, and The Return of the Jedi King). Featuring occasional appearances by Monty Python.
 * Big French Loser. That is all.
 * Hello Cthulhu. Yes, it's Cthulhu and Co in Hello Kitty 'Verse.
 * Teknomorphs is, as you might have guessed from the title, a blending of the 'Verse of Animorphs with that of Teknoman. Although it differs in that the Animorphs gain two new members rather than being replaced.
 * Falling Stars dumps Lucky Star characters into the Fallout universe circa Fallout 3.
 * Babylon Park is set aboard the Babylon 5 space station, populated by South Park-style versions of the characters.

""Do you want the cheesy spoo?""
 * And don't forget

"Oh MY God… We killed Qui-Gon!"
 * Sith Park, from Dork Tower. There's even a T-shirt.

"anon1: Signs. Oh god, my sides. anon2: It really doesn't matter which race is replaced with Orks, does it? Either way the movie becomes half as long and fifty times more entertaining."
 * Also, "Everything's Better With Cthulhu"
 * One Black Lagoon parody covers features Revy and Balalaika in a Mari-mite-like setting.
 * RPG.net archives collected lots of crossovers: One version of TriCalvin, KingdomKarts. Warhammer 40,000 tends to be mixed more often than others, so there are Warhammer 40chibi, three-in-one "In the grim future of Hello Vader..." and even a picture of Tux in WH40K + Bunnies and Burrows + BESM. But In the grim future of Hello Kitty there is only SAN loss.
 * /tg/ loves those, and generates a lot.
 * Major Tom - An undead (and somewhat insane) astronaut (name taken from David Bowie's song) lands in a Dungeons & Dragons campaign.
 * "Brothers! Like the frog which leaps! Forward!" (Starship Troopers + knightly orders on Magitek).
 * This has "basically, Skynet meets The Brave Little Toaster" (also on Magitek, in a sidetrack of the thread about a computer made out of undead skeletons).
 * "Greencaps" (Dungeons & Dragons + Apocalypse Now, on account of Kobolds sharing the methods of Viet Cong).
 * these stories (Nana's Everyday Life+Team Fortress 2).
 * "The Palinka Effect" (Blue Rose or any other utopian setting X Balkans)
 * And another trolling crossover, Blue Rose X The Culture ("You play the Aldean equivalent of the CIA").
 * Mindflayer Twilight. Yes, it's Twilight where a vampire is replaced with a mindflayer. Ella apparently is... uh... perfectly safe with William.
 * Wisdom of the Great Frog ("Rikki Tikki Tavi in a fantasy setting, plus a healthy dash of political intrigue, and delivered by way of Terry Pratchett")
 * Warhammer 40,000 variations still lead, ranging from raw concepts to several chapters long stories.
 * "My Little Heretic" (My Little Pony: Friendship Is Magic + "Cultist-chan")
 * "Hugz an gaussez..." Reimagining of My Immortal as a Necron fanfic.
 * Things the Imperial Guard is no longer allowed to do - Skippy's List inspired madness adapted for 40k.
 * DC 40k - starts with a question "If the Night Lords are super-edgy 80s Batman clones in 40K, what would be the equivalent of a super-campy 60s Batman clone in 40K?", and rolls toward "...and a generic sleazy Imperial noble as Penguin."
 * [//archive.4plebs.org/tg/thread/66619228/#66621280 Stranded space marines and orks in Star Wars].
 * [//1d4chan.org/wiki/Story:Full_Melta_Panic Full Melta Panic] (Love Can Bloom + Full Metal Panic!)
 * In the grim smurfness... ...of the 41st millennium, there is only Ultrasmurfs.
 * From Luth: "Hatsune Miku [//boltertokokoro.tumblr.com/post/183062380022/drawing-from-todays-drawthread-26022019 (as a Sororita) … Swinging a giant leek at a heretic"; also, [//boltertokokoro.tumblr.com/post/183714994892/drawings-from-drawthread-2632019 surfing on a giant leek]. Metal Boxes Solid ([//www.deviantart.com/lutherniel/art/Metal-Boxes-Solid-781834912 here]). Link from The Legend of Zelda (animation) [//boltertokokoro.tumblr.com/post/183695261802/link-from-the-legend-of-zelda-animated-series-as as Aspect Warrior]. //boltertokokoro.tumblr.com/post/184144881782/i-am-alpharius-and-you-are-too-drew-this Alpharius in a scene of [[Metal Gear Solid. [//boltertokokoro.tumblr.com/post/184398858327/psyker-megumin Psyker] Megumin. KonoSuba Wiz [//boltertokokoro.tumblr.com/post/184863357392/drawings-from-drawthread-1452019 as Eldar Farseer]. [//boltertokokoro.tumblr.com/post/185354387762/drawings-from-drawthread-462019 Cadian] Haruhi Suzumiya. Also, "[//boltertokokoro.tumblr.com/post/187134472387/i-drew-a-ratling a ratling]" (Chip 'n Dale Rescue Auxilia?). And the other way around: [//boltertokokoro.tumblr.com/post/190246606872/drawings-from-drawthread-1412020 Leman Russ as gym teacher, SM and CSM rap battle], [//boltertokokoro.tumblr.com/post/180777924007/drawings-done-in-this-weeks-drawthread Celestine in a rap battle], [//boltertokokoro.tumblr.com/post/190246606872/drawings-from-drawthread-1412020 Bat-Ork].
 * This extends to whole games, such as:
 * Adeptus Evangelion (Neon Genesis Evangelion via Dark Heresy, inspired by the Shinji and Warhammer40k) and Dungeons: The Dragoning, "that takes elements from quite a few places, mostly Dungeons & Dragons, Exalted, 7th Sea, World of Darkness, Deadlands and Dark Heresy"
 * Or more specifically, Orkification (which tend to turn anything into a slapstick comedy).
 * "[//1d4chan.org/wiki/Ork_fikkshun Ork Fikkshun]" (Pulp Fiction with Orkz - "Oi, Gromgark, you know wot dem 'umies call dere shootas?")
 * "Da Legend of Moby Git". Moby Dick... with orks.
 * "Borks". The Borg attempt to assimilate the Orks, with hilarious results.
 * "Take the last film you watched. Replace the main characters with Orks." thread.


 * …Of course, some of these movies already differ from Gorkamorka mainly in paint scheme and amount of spiky bitz. Like Deff Race, or REDLINE, or...

"anon1: Mystery Science Theater 3000: Warrior of the Lost World. anon1: "We gots to get us one a dem MEGAWEAPONS! WAAAAAAAAAAAAUUUUUUUGGGGGHHHH!" anon2: Megaweapon is so Orky it isn't even funny. anon3: Slap on some red and perfect."


 * Shinji and Warhammer40k fanfic.
 * 24 Hour RPG Movie Mashup Competition on The Free RPG Blog (individual entries with links are posted on the blog - click on the tags, e.g. "24hour"). Such as...
 * "All the King's Men" (Apocalypse Now + Robin Hood)
 * "Alone in the Woods" (Home Alone +Robin Hood: Men in Tights)
 * "Djinnbusters" (Disney's Aladdin + Ghostbusters)
 * "The Droog Family Songbook" (Clockwork Orange + The Sound of Music)
 * "A Fistful of Darkness" (A Fistful of Dollars + Dark City)
 * "The Great Garbage War" (Mars Attacks! + WALL-E)
 * "Princes of Arabia" (Aladdin + Raiders of the Lost Ark)
 * "Spade vs. Indy" (Indiana Jones + The Maltese Falcon)
 * "West Side Horror" (West Side Story + Little Shop of Horrors)
 * There is a Death Note doujinshi which parodies Onegai My Melody. It's called (obviously) Onegai! Near Mellody (yes, Near plays Kuromi and Mello plays My Melody).
 * Supah Nario Bros is Naruto if all the characters were mixed with Super Mario Bros. characters (Naruto becomes Nario, Sasuke becomes Princess Toadsuke, Lee becomes Leegi and so on).
 * What really happened to... ...Ahsoka Tano before order 66. Those poor Daleks...
 * Advent Cirno, by the Doujin circle One Night Stand, is an ongoing Touhou take on Final Fantasy VII, with everybody's favorite Baka standing in for Cloud and fighting monsters alongside a Nakama composed of Hong Meiling, and Reisen and Tewi Inaba, along with some other familiar Touhou faces.
 * There's also 30 by Wi-Z GARAGE, which takes the plot of Mountain of Faith and combines it with Three Hundred, with awesome results.
 * Obscure doujinshi series Mythic Quest has a whole non-canonical edition crossing over with .hack, which involves Anaya as Emma Weilant and John as Harald Hoerwick, along with other omakes of Balmung as their son and .hacks Aura as their daughter. (What with them having a canonical AI-daughter, it's not a hard stretch to make. Her also being named Aura means the author just wasn't trying.)
 * xkcd has this (see the Alt Text). And this.
 * El Goonish Shive Q&A #5 has Doctor Who-lmes ()
 * The Pokémon fanfic Brave New World is basically Characters from the anime in a Darker and Edgier version of the Pokémon Mystery Dungeon world (with a dash of Redwall) starring in a Darker and Edgier version of Paper Mario: The Thousand-Year Door.
 * The Legend of Eevee: Pokéflute of Time is exactly what it sounds like: Ocarina of Time with Pokémon. And copious amounts of Rule of Funny.
 * There was a rather terrifying and dark doujinshi based around fusing the concepts of Azumanga Daioh and Drifting Classroom. The results (rape, trauma, ) made for a disturbing, yet oddly compelling read.
 * The crossover fanfic A Dark Knight Over Sin City explores the concept of Batman and his rogues in Sin City.
 * Renegade takes the Mass Effect setting and replaces Systems Alliance Earth with Tiberium Earth. Changes abound, with a heavily militarized humanity who doesn't align with the Citadel, the Brotherhood of Nod operating in the background, and apparently
 * This has actually become a somewhat popular theme to do in Mass Effect fandom: how would another faction, such as the UNSC from Halo, or the United Federation Of Planets handle being put into the place of the Systems Alliance?
 * In the case of the former, there's The Last Spartan, in which Master Chief is thawed out 131 years after the events of Halo 3 to find the UNSC has been renamed the System Alliance due to a serious reorganization overhaul and has thus joined the Citadel. The lynchpin of this canon fusion is The Chief functionally filling the role of Commander Shepard.
 * The "Elementary, My Dear Natsuki" series has My-HiME characters taking the place of Sherlock Holmes regulars.
 * Head Trip presents: Broke-batman-tain.
 * Ascension is essentially Neon Genesis Evangelion in the Half Life setting with copious amounts of Space Opera thrown into the mix along with a Kamina-esque Kaworu switching places with Shinji in order of appearance.
 * JohnSu on Deviant ART gave us Desu Note.
 * This is rather popular with the Homestuck fandom, given the nature of its primary plot element.
 * This video will provably (if hadn't done yet) spawn one or two fanfics mixing 2001: A Space Odyssey and Vocaloid
 * Hijinks Ensue came up with "Care Ewoks vs. Death Star" theory as the answer to No Endor Holocaust debates.
 * Pinocchio, Vampire Slayer.
 * See also the comment on Unshelved.
 * Fics that involve the concept of His Dark Materials daemons translated into other continuities are surprisingly common.
 * Feli Summons Paini's Cupcake.
 * Also Law Abiding Engineer
 * Fallout Equestria presents an alternate future of My Little Pony Friendship Is Magic mixed with Fallout, with a bit of 1984 thrown in for good measure.
 * There's also World of Ponycraft
 * Pony Space
 * Pony Age: Origins
 * Silent Ponyville
 * Pony Effect
 * The Luna Heresy
 * Friends of a Solar Empire...
 * Po-Ni-Oh! The Abridged Series
 * This is pretty common in Guyver fanfics. Which amounts to "_____ becomes The Guyver." There have been fan fics where the likes of Misato Katsuragi, Lucy, and yes, Ranma, have become hosts to The Guyver unit.
 * Sucker Punch cast with human versions of The Penguins of Madagascar: Omega Boom.
 * Sinfest proposes three slasher comics (as in, Slasher Movie + Comic, not slashfic).
 * Nerf Now had Team Fortress 2 + Pokémon arc, the one about Blue Engie's niece. ("P.S.: Don't let her have a pet.")
 * Decks Fall Everyone Dies has the characters of Yu-Gi-Oh!: The Abridged Series in the general plot from Moulin Rouge.
 * Mini-Mythos by Kenneth Hite, a series of books that fuse the Cthulhu Mythos with popular kiddies' picture books. Where The Deep Ones Are, The Antarctic Express, and Cliffourd The Big Red God.
 * This Fanfiction seems to blend pretty well, but the universes are total opposites
 * And don't forget this one by the same author, these are both improbable, due to the fact they are animation/live action crossovers, with shows on competitive channels
 * And especially this
 * My guess is probably cause of the author, who seems to have a kajillion of these crazy ideas up their sleeve, cause all three are by the same author
 * You forgot the sequel to the first one listed here it is
 * The Last Spartan story is a nice blend between the Halo and Mass Effect universe, staring Master Chief as Commander Shepard.
 * Anzai's School for Gifted Basketball Players: So what would happen if all Slam Dunk characters were mutants and joined their respective sides? This appears to be either a tongue-in-cheek parody of this genre, or perhaps simply just a Crack Fic. Nonetheless, the characterizations are actually quite spot on while managing to incorporate each mutant's quirks.
 * An official one: the DC Elseworlds tale Superman's Metropolis. Superman and his supporting cast in the setting of Metropolis.
 * "It's Five By Five" is a crossover of Dragon Age II with Angel. It features Anders/Vengeance as Angel/Angelus, Sebastian as Holtz, Female!Hawke as Buffy, Alistair as the Mayor of Sunnydale (for some inexplicable reason), Carver as a vampire...
 * Lantern Prime has Optimus Prime as the indirect source of the Manhunter robots and the first Green Lantern.
 * An interesting example is Coming Forward, a Paper Mario: The Thousand-Year Door fic by krisetchers. The author got a few chapters in when he realized, purely by coincidence, that his fic had the exact same plot as Final Destination. He decided that the only proper thing to do was to retroactively make it a Fusion Fic, even though the fic is in fact a sequel to another fic which has nothing to do with Final Destination. Unfortunately, this means that some really early plot points are forgotten and never mentioned again.
 * There is an adaptation of the Body Horror movie The Thing with the characters of the Claymation childrens show Pingu. It is as insane and hilarious as it sounds.
 * There's the Avengers fic The Snow Queen By Elspethdixon, which has seven chapters: A mirror of steel, A Soldier and a Smith, Of the Library At the Young Woman's Who Understood Witchcraft, The Prince and the Princess, The Little Robber Boy, The Far North, and Who the Soldier Met There, and Of the Metal Woman's Palace and What Happened Afterward. It's basically the Hans Christian Anderson story told with Captain America (comics) as Gerda, Iron Man as Kay, and various Avengers, Avengers villains, and other superheroes as all the supporting characters (several of whom don't appear in the original story, but fit perfectly into the original story's various settings). It's written in a very authentic, fairy-tale-ish style similar to Anderson's, and it's actually quite a serious and angsty story, even though it's crammed full of delightful in-jokes, and Avengers fans will take great delight in recognizing which Marvel characters the usually vaguely described and nameless or ambiguously-named supporting characters are supposed to be (hint: the great number of insect- and animal-based codenames given to Marvel superheroes fits this story very well).
 * Super Mario XP takes elements from the Castlevania series and mixes it with Super Mario Bros.
 * Calvin & Muad'Dib. Here. What Do You Mean It Wasn't Made on Melange Coffee?
 * My Little Fortress: Friendship is Magma (Dwarf Fortress mod with My Little Pony: Friendship Is Magic and... some other stuff).
 * My Mandalorian Ponies. (cosplay that ended up in Questionable Fan Art section of Superdickery.com)
 * The 1983 Doomsday Stories AU combines Axis Powers Hetalia with the post-apocalyptic universe of 1983: Doomsday. The end result isn't exactly what one would expect.
 * Code Geass 50K: Lelouch of the Imperium (link) is a Warhammer 40,000 Bad Future fic in which Lelouch is the Emperor of Mankind, with the events of the anime itself being the distant past of the Warhammer universe. These turn out to have dramatic repercussions, even if it takes thousands of years to unfold.
 * Alice down the portal hole by Daeg-Niht.
 * An In-Universe example from Schlock Mercenary (not clear whether it's intentional or not): a "retro RPG" called Rosencrantz and Guildenstern Are Hobbits.
 * There are mashups of Kinnikuman and Street Fighter characters in Kinnikuman: Muscle Fight. These include a version of Ramenman with Guile's moveset, Puripulsim, Sagashine , Vegaken Jr. . These characters are considered joke characters since they barely do any damage in comparison to the canon characters.
 * [//aiweirdness.com/post/141313469232/cooking-with-cthulhu Cooking with Cthulhu] and [//aiweirdness.com/post/158952162057/cthulhu-in-the-kitchen Cthulhu in the Kitchen] — a neural network trained on the complete works of H. P. Lovecraft makes up cookbook recipes, then a neural network trained on 30MB of cookbook recipes was given phrases from Lovecraftian horror.
 * Astral Journey: It's Complicated, despite being an Alternate Universe Fic of the Spice Girls, many other 90s artists are also featured.
 * Cruising for a Jobbing, a mix between and WWE.
 * The Wild Horse Thesis takes Ranma Saotome of Ranma ½ and inserts him into the role of Shinji Ikari in Neon Genesis Evangelion. Interestingly, this insertion takes place In-Universe for the other characters of Ranma ½, who get to watch Ranma's efforts to derail Third Impact on a special set of Evangelion videotapes delivered to the Tendo home.
 * Final Stand of Death bring most of the folks featured on Celebrity Deathmatch, Let's Play, Planet Dolan, WWE and so into one.
 * Full Frontal Nerdity had Avengers team as Team Fortress 2 characters discussed here.