One of the rules of fanfiction is anyone can be the main character, even if they had three seconds of screentime in the source material.

* ''FanFic/SlightlyAltered'' has Samantha Kailum and Toby, who barely get any screen time in canon, promoted to ThreeAmigos status with Buwaro.
* In the ComicBook/{{X-Men}} fanfic ''FanFic/MutatisMutandis'', the author mentions that initially Jean-Paul was supposed to be Rogue's snarky best friend and moral compass but realized he was described in a way that did not lend himself to such a role. Thus, Victor (Anole) became the [[RedOniBlueOni blue oni to Anna's red]].
* ''FanFic/HarryPotterAndTheMethodsOfRationality'' does this a fair bit; some characters with only background roles in the original series have much more fleshed out parts, most notably Blaise Zabini.
* The Supetastic 6 were just in an animated special of the same name in Series/TheNakedBrothersBand, now they're recurring characters in [[http://alaxr274.deviantart.com/gallery/33810717 Super Milestone Wars]] with Captain Music as the SupportingLeader. In it's sequel, they're are the main protagonists.
* ''Fanfic/{{Luminosity}}'' diverges from the plot of the ''Literature/{{Twilight}}'' novels radically enough that this is almost a guarantee. One notable example would be Gianna, whom ''Twilight'' fans would know as that woman who was in the Volturi's waiting room and whom ''Luminosity'' fans would immediately recognize--her brother Ilario gets a role, she's [[spoiler:Elspeth's]] mother, she's [[spoiler:Maggie's mate]]...
* Ever since Blaise Zabini shared a train compartment with Draco, he's shown up in countless fanfics as Draco's BFF. This is particularly noticeable when authors fail to get the few facts we do know about him, such as his dark skin or the fact that his mother has married seven times (with a very strong implication that she's a BlackWidow).
* In ''DragonAgeTheCrownOfThorns'', [[spoiler:Trian Aeducan does not die]] because of the [[spoiler:ZeroApprovalGambit]] that the GuileHero / MagnificentBastard protagonist pulled off. He [[spoiler:grows into a very likable WisePrince later on, although, true enough, he goes through a several months-long BreakTheHaughty process first.]]
* In the ''Series/ForeverKnight'' {{continuation}} ''FanFic/FK4'', Urs, a vampire character who appeared in four episodes of Season 3, becomes part of the main cast.
* ''Fanfic/{{XSGCOM}}'' does this a lot. For example, central character [[FourStarBadass Commander Russell Sharp]] was merely a throwaway mention in a ''{{X-COM}}'' manual.
* [[http://www.fanfiction.net/s/7292991/1/Xanatos This]] ''Manga/DeathNote'' fanfic does this with Matt, who went from OneSceneWonder of 16-panel and 30-second fame in canon to becoming one of the main characters. In fact, [[spoiler: L needs him specifically to not only solve the Kira investigation, but also to resolve the tension between Near and Mello.]]
** And then there's Linda[[note]]A literal OneSceneWonder who doesn't even appear in the anime[[/note]], who also seems to be a central character. [[spoiler: though as of late she's been PutOnABus]].
* ''FanFic/WinterWar'' has a lot of these, ranging from [[MinorMajorCharacter Minor Major Characterss]] like Sasakibe, who goes from "the Lieutenant of First Division who never does anything" to a more fleshed-out character and a mainstay of LaResistance, to characters who had brief importance in canon and haven't been seen since (Shiba Kuukaku, Rikichi, ''Inoue Sora'') and become pivotal again in the fic, to {{Omake}} characters like Shirogane and Ogidou getting personalities and plot importance, to literal Ascended Extras like [[LesCollaborateurs Ito]]- who seems to be the nameless guy with the blond mohawk in [[http://www.youtube.com/watch?v=LWI4qQHQhbw the Eleventh Division ending of the anime]].
* Lily from ''FanFic/PokemonMysteryDungeonSilverResistance''. First she was submitted as a potential character for the prequel, ''Emerald Chronicles''. After that, she starts appearing in the main story, eventually joining the main characters on their quest.
* ''FanFic/ErisGame'' makes Eri, Shiki's best friend, the main character and narrator of this fanfic.
* The ''Fanfic/DeliverUsFromEvilSeries'' gives a veritable ''[[LoadsAndLoadsOfCharacters host]]'' of Ascended Extras from the Literature/SherlockHolmes {{Canon}}. The first novel alone has Inspector Patterson, from one mention in "The Final Problem" to full supporting character status; Wiggins, from two brief scenes in the first two Literature/SherlockHolmes novels to another supporting character; InspectorLestrade, from recurring character to Deuteragonist (one of the leading points-of-view in the novel); Mary Watson and Mrs. Hudson, from recurring extras to supporting characters. Moriarty and Moran also get a ''lot'' of screen-time, and Culverton Smith has a bigger status as the villain for the first quarter of the novel.
** ''The Road to Reichenbach'' is meant to be starring several Scotland Yarders from the Canon, and these characters should maintain their prominent status throughout the rest of the series.
** ''To Take Up the Pen'', the future third novel in the series, will up the ante further with Colonel Moriarty, a character who receives only one clear mention in the Canon, and Colonel Hayter, a OneSceneWonder from one of the short stories. Also, Colonel Moran (yes, that's a lot of colonels, but they're all canonical) ascends to BigBad status as he chases Holmes across Europe and Asia.
* ''Fanfic/GameTheory'' has quite a few. Tiida Lanster, Quint Nakajima, Megane Alpine, Linith, and Nanoha's mother were all fairly minor characters in canon, but they've been given significantly expanded roles in this story. But the most prominent example is [[spoiler:Vesta, [[OCStandIn who was just a nameless kitten in the original work]]. In ''Game Theory'' she becomes Nanoha's familiar.]]
** Not to mention [[spoiler:Alicia Testarossa]] in the sequel.
* In ''Fanfic/NoHoper'', a ''Manga/DeathNote'' and ''TheHouseOfNight'' {{Crossover}}, [[WhatHappenedToTheMouse Kayla]] becomes a proper character again. Also Yamamoto-Light's friend from school who appears in a few pages of the manga and doesn't appear in the anime-is one of the few other characters that makes a showing from ''Manga/DeathNote'' canon. As for from ''TheHouseOfNight'' canon, Drew Partain - who'd only gotten a couple of mentions as Stevie Rae's [[ShipTease maybe boyfriend]] in the books - and 'Amanda', who only ever had one mention in the first book.
* ''FanFic/MyLittleMagesTheNightmaresReturn'': [[DarkActionGirl Nightshade]] is, according to WordOfGod, based on the lead illusionary Shadowbolt created by Nightmare Moon in the second part of [[WesternAnimation/MyLittlePonyFriendshipIsMagic the show's]] pilot. Said character had less than half-a-dozen lines and was only around for less than two minutes in the show; here, she's a member of the QuirkyMinibossSquad.
* ''Fanfic/TheLegacyOfTheBloodRavens'' expands the roles of characters that are only mentioned or have few lines. Oddly enough, this is even the case for the Force Commander Aramus, who has [[HeroicMime no lines]] in the games themselves.
* ''Fanfic/EqualAndOppositeAttraction'' has Alyssa and Suzuka, originally ThoseTwoGuys from Nanoha. Now they are taking magic lessons from Negi.
* ''Fanfic/YuGiOhForever'' gives us Gozaburo Kaiba, Seto and Mokuba's adopted father. In the original manga he was an extremely minor character who's revealed to be [[AbusiveParents the reason]] Seto's such a colossal JerkAss, and who's briefly shown as having been DrivenToSuicide following a hostile takeover of Kaiba Corporation by Seto. In the anime, his role was expanded upon somewhat in the filler Virtual World arc where he proved to be the ManBehindTheMan for his biological son Noah, but even then he was still a relatively minor character compared to the heavier hitters in the non-filler episodes. In this fanfic, however, he gets a significant boost in importance: [[spoiler:he's the BigBad for the entire story, with [[TheChessmaster chessmaster skills]] that incorporated [[CrazyPrepared even the possibility of his defeat in the aforementioned Virtual World arc]] into his plans, where in the story's timeline he reveals himself to have been NotQuiteDead after all, and newly DangerouslyGenreSavvy to boot]].
* The SuiteLifeOnDeck story "Life Unexpected" uses Reina, who appeared in exactly one episode as the antagonist, becomes Bailey's best friend and even given a developed backstory making her the child of a teen pregnancy. This was the main driving force behind their friendship as she sympathized was Bailey who was pregnant.
** In general Suite Life fanfiction this is true of the character of Max, who appeared in only six episodes of the very long series. Partially due to being played Alyson Stoner, partially due to her DeadpanSnarker nature, and partially due to being more bearable than GirlOfTheWeek Zack was with.
* The ''Literature/SherlockHolmes''/''Series/DoctorWho'' crossover ''Fanfic/ChildrenOfTime'' features Sally Sparrow, the heroine of [[Recap/DoctorWhoS29E10Blink "Blink"]] in a prominent role. After the series' AU of "Blink", she marries Dr. Watson (her co-star in said AU) and becomes the CoolBigSis to Beth Lestrade as well as the TeamMom to the Irregulars. And that's not even mentioning the baby...!
* ''FanFic/RainboomsAndRoyalty'': [[EnsembleDarkhorse Ditzy Doo/Derpy Hooves]] ends up playing a major role in the story, and becomes a prominent secondary character in the sequels.
** Zecora, while not an extra on the show, gets a much expanded role in the story.
* ''FanFic/DeathNoteEquestria'' has Straw Bolt -- originally created for filler dialogue, he becomes a POV character.
* In the ''Fanfic/TeenTitansSaga'', General Immortus -- who did practically nothing in canon -- is made the BigBad of the second story, ''The Art of War''. [[WordOfGod The author has said]] that this is directly in response to the show [[TheyWastedAPerfectlyGoodCharacter wasting him]].
* Several {{Franchise/Sonic|TheHedgehog}} characters that were hardly featured [[VideoGame/SonicGenerations in the original game]] play important roles in ''FanFic/SonicGenerationsFriendshipIsTimeless'', such as [[VideoGame/SonicAdventure Big, Chaos, Tikal]] and [[VideoGame/SonicHeroes Omega]] in chapter 10 and [[VideoGame/SonicRushSeries Marine]] in chapter 14.
* The ''Literature/ASongOfIceAndFire'' ContinuationFic ''Fanfic/TheNorthRemembers'' contains most of the familiar POV characters from previous books in the series, but adds in some new ones to give a viewpoint at certain places where no other existing POV could be at.
** Val for The Wall [[spoiler:after Jon Snow's death at the hands of his brothers.]]
** Jeyne Westerling for Greywater Watch [[spoiler:and eventually White Harbour.]]
** Sandor Clegane for the Riverlands and King's Landing [[spoiler: where he hopes to kill off his undead brother.]]
** Ramsay Bolton for Winterfell [[spoiler:after Theon Greyjoy escaped with Jeyne Poole.]]
** Willas Tyrell for Highgarden.
* ''FanFic/AGrowingAffection'' makes Yugao Uzuki a major supporting character. She has a romantic subplot, gets her own team, and gets a BackStory linking her to Anko and Iruka. Who also appear in a more pivotal role in this story.
* In ''Videogame/MegaManZero'', Colbor originally existed to be rescued from Harpuia. In the Videogame/MegaManZX fanfic ''Fanfic/RiseOfTheChosen'', he is shown to be one of the Guardians' best commanders, second only to Prairie.
* The ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fanfic ''FanFic/TheVinylScratchTapes'' turns the spotlight on DJ-P0n3 and Octavia. In canon, these characters have had only brief {{cameo}}s with no dialogue, and they haven't even met. In the fic, they become VitriolicBestBuds.[[spoiler:..and eventually move in together.]]
* ''FanFic/TheFanmakeBlooperSeries'' has this twofold with Film/VanHelsing. The first fold is that the role he had in a Disney/SleepingBeauty FilmFic was a nameless guard, but decided to bump his significance up by shooting [[WesternAnimation/MyLittlePonyFriendshipIsMagic Queen Chrysalis]] (who was playing Maleficent) and the second fold because from there, he turned from a guy who did one action and only said one line to becoming the closest thing [[EnsembleCast any of the main characters]] has to TheMentor as well as a recurring character for the rest of the series.
* TheVampireDiaries fanfic Love Bites, So Do I does this was with Tina and Blair, two minor characters from one episode who had one line a piece. [[TheOtherDarrin although recasted]], they are made into the main character's older sisters while Tina dates Damon [[spoiler: before having a baby with Matt]] and Blair is actually a werewolf. Later chapters use Valerie Fell, who has NO lines and appeared for all of 3 seconds at most.
* In the ''Literature/{{Discworld}}'' ExpandedUniverse of author A.A. Pessimal, Ascended Extras who may be no more than throwaway names and non-speaking one-line spear-carriers in Canon become rounded-out central characters alongside the established cast. some, like [[UsefulNotes/SouthAfrica Howondalandian]] Assassin Johanna Smith-Rhodes have become stars in their own right; a recurring line in reviews by fans is that they can't see the join where Pratchett ends and Pessimal begins.
* In [[http://www.fanfiction.net/s/5695115/1/MMZX3-Mega-Man-ZX-Enforcers Mega Man ZX Enforcers]], Biometal Model O, a non-canon "bonus" Biometal in the first ZX game, is stated as having been stolen from the Guardians alongside Models F, L, H, and P (thus technically making Vent and Aile's acquisition of it canon by this story's standards), but had no Biomatch and was thrown out. Model O is now used by Taylor, a new main character. Model O actually speaks in this story, but is FAR calmer than [[VideoGame/MegaManZero the Reploid he's based on]].
* In ''VisualNovel/ApolloJustice'' fanfic ''Fanfic/DirtySympathy'', Plum Kitaki becomes a major character after she offers her resources to help Klavier and Apollo with their StrangersOnATrainPlotMurder after they save her son, Wocky.
* The ''Manga/MedakaBox'' fanfic ''Fanfic/WorldAsMyth'' takes this UpToEleven; probably half of the canon cast (protagonists and villains alike) are shuffled out for characters who only had bit parts in the original manga. Surprisingly, everyone stays in character even so. [[AlternativeCharacterInterpretation Most of the time]].
* In ''FanFic/MegaManRecut'', Doc the Metool, referred to in this story simply as Met, becomes a recurring character rather than a one-shot character like in the show. Additionally, many guest Robot Masters gain more screentime, and thus more personality, as do many cartoon-exclusive humans.
** The cosmetics robot from "Electric Nightmare" is slated for future appearances.
* In ''FanFic/MegaManDefenderOfTheHumanRace'', Doc the Metool, who only appeared in the first episode of the show, is here a more prominent character who bonds deeply with Roll. [[spoiler:And then he dies]].
** Newswoman Bree Ricotta gets a lot more screentime, as do other cartoon-exclusive humans.
** Oneshot crook Ms. Lapierre returns in episode 7, having stolen Knight Man.
** In a non-show example, the Mad Grinder from Mega Man 7 appeared only in the game's intro, serving as a warmup boss. In the fanfic, the Mad Grinder is [[spoiler:Project G-2, and is as tall as he was in the intro cutscene]].
* In ''[[FanFic/PokemonMysteryDungeonReflectingBalance Pokémon Mystery Dungeon: Reflecting Balace]]'', Kala the Abra was introduced as a Pokémon working at the Rescue Team HQ, serving the purpose of teleporting rescue teams to far-away dungeons. While this was originally going to be her only role, the writer ended up expanding Kala's role in the story once another character needed someone who could teach them how to use their telepathy to communicate, and Kala happened to be the perfect character for the part.
** There's also Hercules the Heracross, who had this happen to him ''before'' his debut chapter was even written, due to the writer having the idea of making him Blitz's mentor and [[TheConfidant confidant]] when she was working on the first few chapters, which ended up promoting him from minor character to major supporting character.
* ''FanFic/YoungJusticeDarknessFalls'' gives us several ascended characters.
** the Kents both have a minor role in the fic.
** Jason Todd [[spoiler: comes BackFromTheDead, and even has a central role in stopping the apocalypse.]]
** Beast Boy gets his own character arc and a much larger part in the story overall.
** Darkseid only appears in the last episode of the show, but in this fic, he takes over as BigBad as his actions are much more important than anything the light is doing.
** Wonder Girl wasn't exactly central to the show except as "general muscle". Here, her relationship with Robin is expanded on from the LastMinuteHookUp, and we get to see her in action more.
** For that matter, the league features much more prominently overall. Superman, Wonder Woman and Batman get back in the spotlight, Zatanna gets some more things to do both alone and in connection to Dr. Fate, Martian Manhunter takes up a role of mentor, and even the green lanterns, perhaps the least seen of the heroes get screen time and action.
* ''Fanfic/ANewChanceSeries'': Latios and Latias, who made an appearance in the 5th movie, join Ash's team for the rest of Johto and then to Hoenn.
** Bianca, the girl who played a minor role in the 5th Pokemon Movie as well [[spoiler: as the girl whom Latias based her human form on]] becomes a recurring character in the first story in the series, and goes on to join Ash on his journey to Hoenn in the second story.
* ''Fanfic/{{Bait and Switch|STO}}'' borrows the names and faces of some of its {{Red Shirt}}s and {{Mauve Shirt}}s from ''VideoGame/StarTrekOnline's'' list of randomly generated duty officers, the RedShirtArmy that run your lower decks and have even less characterization than your bridge officers generally do.
* ''CodeGeassMegiddo'' expands the roles of several minor characters in addition to the numerous OriginalCharacters that flesh the story out. Of note are the Knights of the Round, particularly Dorothea Ernst, who at the most got thirty seconds of free time in the series proper. Here, she has a brother who doubles as the Knight of Two that is a ''very'' capable strategist, to the point that here, he is the ''only'' person besides Schneizel to beat Lelouch in chess (they only ever played one game, but still...). Dorothea is also [[spoiler:the secret wife of the Knight of One, Bismark Waldstein, and the mother of his child, Roland. She also got along with Lelouch, who was Bismark's student during the eight years his memories were suppressed, and held him in such high esteem that she allowed him to hold their child; she's also aware that Lelouch is Zero, and like Bismarck, is conflicted knowing that they will eventually have to face him in battle.]]
* In ''WesternAnimation/DannyPhantom'', Tucker's wished for ghost half was considered as disposable as anything else Desiree conjured up, but in the ''FanFic/FacingTheFutureSeries'', he becomes a villain in his own right.
** Danielle as well, who makes a few more appearances and [[spoiler: and ends up being adopted by the Fentons, joining Team Phantom.]]
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