%% This page is now alphabetized.
%% Please remember to add context (how is the character's narrative role increased?) before un-commenting examples.

FanFic writers love to make their favorite characters [[AdaptationalBadass far more badass]] when they're the ones writing them.

%%[[AC: ''Manga/AhMyGoddess'']]
%% Needs more context. How does this Fic make him more of a Badass?
%%* ''Fanfic/AhArchfall'' makes Keiichi a bit more impressive by

[[AC: ''VideoGame/BackyardSports'']]
* Jorge Garcia in ''Fanfic/TheSecretLifeOfTheBackyardKids''. He outruns Pablo Sanchez on all fours, gets superpowers, and basically becomes Bricksfield's equivalent of Franchise/{{Zorro}}.

* Stephanie Brown in ''Macushla''. After her father is killed for unknown reasons by the League of Shadows, she's taken to serve under Talia al Ghul. She's a master assassin before she's 18 years old and becomes Damian Wayne's bodyguard/MoralityPet. (After [[spoiler:Talia fakes Stephanie's death and sends her away because she and Damian were too close, he leaves the League and asks to join Dick Grayson of his own will]]).
* Minor character Salvatore Maroni gets this in ''FanFic/BatmanRevisited'', as he is [[CompositeCharacter the supervillain Firefly]] here, and considered a dangerous enough threat to be locked up with [[ImprobableAimingSkills Deadshot]] and ''Killer Croc'' in a maximum security wing of Blackgate Penitentiary.

[[AC: ''Anime/BattleOfThePlanets'']]
* Security Chief Anderson in the ''[[http://archiveofourown.org/series/394162 Battle of the Planets:2163]]'' arc gets an upgrade to badass on the grounds that you don't get to be the Chief of Galaxy Security by being a nice person. He carries a gun and isn't afraid to use it, to the consternation of his staff. He's also TheSnarkKnight which is an extension of some of his better lines in the actual series.

[[AC: ''Disney/TheBlackCauldron'']]
* [[SorcerousOverlord The Horned King]] was a NonActionBigBad in the movie. (A ''[[KnightOfCerebus scary]]'' NonActionBigBad, but still.) In ''Fanfic/HopeForTheHeartless'', which takes place after the movie (with him being ResurrectedForAJob), he gets in several fight scenes, proving in all of them that he's ''[[LightningBruiser not]]'' [[LightningBruiser someone to be trifled with]].

* ''Fanfic/AProtectorsPride'': Ichigo starts the Arrancar arc with access to his Hollow powers. All the the good guys in general are a lot smarter and pragmatic than in canon, especially Chad and Orihime, who are ''not'' useless.
* ''[[https://www.fanfiction.net/s/11021904/1/ White]]'' drastically powers up the Espada. ''Eight'' of the ten are Vasto Lordes and those who were Vasto Lordes in canon are generally more skilled and/or powerful from training with White/Ichigo.
** [[AmazonBrigade Apacci, Loly, and Menoly]] are each barely weaker than the Ninth Espada due to having eaten Yammy prior to becoming Arrancar.

[[AC: ''ComicStrip/CalvinAndHobbes'']]
* Calvin was always a bit adventurous, but his CharacterDevelopment in ''Fanfic/TheCalvinverse'' furthers it, leading to him becoming a GadgeteerGenius and eventually a ManipulativeBastard.

[[AC: ''Anime/CodeGeass'']]
* In the original anime, Lelouch had plenty of courage and was good with a gun, but him being out of shape was a RunningGag and he didn't stand a chance in a fistfight. In ''Fanfic/CodeGeassThePreparedRebellion'', he's much more athletic and quite proficient in martial arts.
* C.C. is outright superhuman in ''[[https://www.fanfiction.net/s/12290311/1/ The Black Emperor]]'' because she can consciously push her body past its normal limits and heal off any damage as it occurs. Likewise, Lelouch is actually fairly athletic and highly skilled with his BladeBelowTheShoulder.
** Later chapters show Milly's a skilled marksman and gains a geass for herself in the second chapter.
** Euphemia not only gains her own geass but is also an observant and intelligent commander from her years following Cornelia from battlefield to battlefield.
* In ''[[https://www.fanfiction.net/s/6200608/1/More-than-just-a-Man More than just a Man]]'' both Lelouch and C.C. are more physically capable than canon. Lelouch is only slightly better, though with far superior hand eye coordination (being able to disable a Knightmare by shooting it's factosphere with a pistol), due to being a newly turned vampire. Meanwhile C.C. is ''far'' more physically capable given that she's an over two thousand year old vampire who has every Geass ability displayed in canon (here, they're vampiric abilities).

[[AC: CrossOver]]
* Several background ponies get turned into much more effective fighters in ''Fanfic/AceCombatEquestriaChronicles''. Especially those flying in the [[AmazonBrigade Mirage squadron]].
* Remember how [[NonActionGuy Yuuno]] was in ''Manga/LyricalNanoha''? In ''Fanfic/BloodThatFlows'', he's easily as badass as any of the main characters and can hold his own against Gods and Demons just as well as any of the other characters in the story.
* In the stories written by Crossoverpairinglover on Fanfiction.net, virtually every character gets upgraded to a point they are badasses. Genuine Lockharts, super saiyan-like Sakuras, Apollos who create black holes, etc.
* Jack in ''Fanfic/CaveStoryVersusIMMeen'', to the point where he becomes a Main/BadassBookworm who literally has the ability to use [[PrecisionFStrike fucking]] ''[[Manga/JojosBizarreAdventure ZA WARUDO.]]''
* ''Fanfic/ChildrenOfAnElderGod'': The three main characters are a bit more heroic and way more badass than their canon counterparts. Shinji pilots his giant robot willingly and gains powers, Asuka becomes a better fighter and gains fire powers, Rei is terrifying...
* While [[Franchise/AceAttorney Shelly De Killer]] was always a skilled assassin, his combat skills get a huge boost in [[https://www.fanfiction.net/s/10849348/1/No-More-Turnabout No More Turnabout]], being able to hold his own against the likes of [[VideoGame/NoMoreHeroes Henry Cooldown and later on, Travis Touchdown]], nearly killing the latter had Sylvia not intervened.
* While Taylor Hebert was already badass in ''Literature/{{Worm}}'', she ups her badassery by several orders of magnitude in ''Fanfic/TheLastDaughter'', where she is actually [[Franchise/{{Superman}} Kryptonian]]. Virtually every fight she's in is a CurbStompBattle in her favor, and she actually manages [[spoiler: to kill ''[[TheJuggernaut Behemoth]]''.]]
* The main Digimon characters from ''Fanfic/DigimonFusionKai'' are [[SuperFic given the ability]] to become beings that look like Super Saiyans.
* While in ''Manga/MahouSenseiNegima'', Ayaka was a self-taught martial artist with her own personal form, she was only Asuna's equal up until CantCatchUp took effect. In ''Fanfic/EqualAndOppositeAttraction'', she becomes a front-line fighter who was trained by Setsuna.
* ''Fanfic/ArcticRim'' does this to [[Disney/{{Frozen}} Anna and Elsa]], the former becoming a CrazyAwesome hilarious badass and Elsa becoming a bona fide BadassInCharge. The Precursors are also a ''lot'' more proactive here than in ''Film/PacificRim'', with one in particular (the story's BigBad) who borders on MagnificentBastard.
* ''[[Fanfic/RyuugisTheGamesWePlay The Games We Play]]'' turns Jaune from ButtMonkey to legitimate badass via the mechanics of ''Webcomic/TheGamer''. In canon, he's far, far behind any of the other main cast. Here, he's able to, among others, beat [[spoiler:Weiss]], turn a DelayingAction against [[spoiler:Penny]] into a win, fight [[spoiler:Pyrrha]] to a draw, bluff his way out of fighting [[spoiler:Cinder Fall]], and outfight [[spoiler:''Raven'']]. And he hasn't even gotten into Beacon yet!
* ''FanFic/TheHeroesOfTime'' does this to the Creator/HannaBarbera universe. Most of the characters in the shared world are rather peaceful people, and never mean harm. But when TheHeartless invade and start swallowing worlds, it's time to take up [[CoolSword Keyblades]] and fight.
* In ''Fanfic/Hottie3TheBestFanFicInTheWorld'', the FanSequel to the novel ''Burning Ambition'' by Jonathan Bernstein, [[TheHero Hottie]] co-pilots her own ''Anime/TengenToppaGurrenLagann''-inspired Gunman. The other co-pilot is ComicBook/SquirrelGirl hersel. She later gains three {{Super Mode}}s, each more powerful than the last. The most powerful SuperMode, Super Hottie Goddess, makes her a PhysicalGod.
* ''FanFic/JustAnUnorthodoxThief'' takes Risei, an intelligent enough character in canon, and tuns him into Tokiomi's HypercompetentSidekick.
* In ''Fanfic/MagicalPonyLyricalTwilight'', [[spoiler:the Nachtwal]] received a massive power and skill boost, including changing its canonical ClippedWingAngel into a proper OneWingedAngel.
* In ''VideoGame/CastlevaniaChroniclesOfSorrow'', the [[TimeMaster Chronomage]] was just a quickly defeated obstacle. In ''Fanfic/MyLittleCastlevania'', he's an active villain, able to fight Aeon one-on-one repeatedly, and wins several times.
* ''Fanfic/NoGodsOnlyGuns'', [[AssInAmbassador Ambassador Donnel Udina]] becomes a full-on GuileHero, humiliating the batarian ambassador in front of the Council, and also possessing an eyepatch and cybernetic hand. Doctor Michel, usually a DistressedDamsel, takes a buzz-axe to the goons threatening her. And Niftu Cal, a volus who claimed to be a biotic god while doped out on drugs, proves himself to be a very powerful biotic who can back up his claims.
* In ''Fanfic/NoHoper'', Light Yagami, a NonActionBigBad in canon, is now [[OurVampiresAreDifferent a vampire with powers over the elements]], a HunterOfHisOwnKind, and a MasterSwordsman.
* Both Shinji and Kaworu in ''Fanfic/ShinjiAndWarhammer40K'' go from canon runty, troubled kids, to nigh-PhysicalGod {{Magnificent Bastard}}s who excel at XanatosSpeedChess.
* While [[Manga/{{Naruto}} Naruto Uzumaki]] has grown into a powerful badass in his own manga, ''Fanfic/ShinobiOfTheHighSeas'' turns him into a ShowyInvincibleHero that manages to go through the Grand Line and ultimately fight Akoji, one of the most powerful admirals in ''Manga/OnePiece'', to a standstill.
* ''FanFic/StormsOverhead'' has Louise and Henrietta get an upgrade; the former packs new Void element spells that [[spoiler: can defy the laws of physics, including matter destruction (or at least, appears to be so)]] while the latter commands her nation with equivalents of modern day policies. Seeing that they're both mentored by a scientist/scholar, it was bound to happen.
* ''Fanfic/ThousandShinji'': In the original ''Evangelion'' show Shinji was a wimp, Rei was properly trained but she was weak, and Asuka was a good warrior but she got her butt kicked constantly. In this crossover with ''TabletopGame/{{Warhammer 40000}}'', the three pilots gain huge powers and take several levels in badass: Shinji becomes a sorcerer with psychic powers, Asuka a berserker super-soldier and Rei a plaguemaster.
* ''Fanfic/TimeLordsAndTerror'', a ''[[WesternAnimation/MyLittlePonyFriendshipIsMagic Friendship is Magic]]'' and ''Series/DoctorWho'' crossover, re-imagines the events of [[WesternAnimation/MyLittlePonyTheMovie the G1 movie]] as a CosmicHorrorStory. Instead of kid-friendly villains, Hydia, Draggle and Reeka are now TheFairFolk-inspired aliens. [[spoiler: They now beat ponies bloody and harvest their life force to awaken the S'Muz (aka the Smooze) an OmnicidalManiac, [[ThePowerOfHate driven by hate]], EldritchAbomination that causes a wave of madness by its mere unsealing, that wants nothing more than destruction of all universes.]]
* In ''Fanfic/{{Unfamiliar}}'', almost every canon character from ''LightNovel/TheFamiliarOfZero'' (but especially Princess Henrietta) gets a massive competence boost and a power upgrade. Considering that they're expected to cope with OneManArmy [[VideoGame/{{Prototype}} Alex Mercer]], this is perfectly understandable.
* In ''Fanfic/JusticeSocietyOfJapan'' while Mordred has a relationship to Morgaine Le Fey similar to how he was depicted in ''WesternAnimation/JusticeLeague'', in this continuity, the preteen is now less of a RoyalBrat and more of a [[UndyingLoyalty Loyal]] ImplacableMan. Also, [[Anime/CodeGeass Shirley Fenette]] has been upgraded from a schoolgirl to one of the main heroes.
* ''Fanfic/LastChildOfKrypton'' does this to plenty of characters, but first and foremost is Shinji Ikari, who turns out to be half-[[Franchise/{{Superman}} Kryptonian]] in the story. Later examples also include [[spoiler: Asuka, Toji, Rei, Kaji, and Naoko Akagi]].
* ''Fanfic/SOE2LoneHeirOfKrypton'': Asuka was the best HumongousMecha pilot in the original story, but she was still a physically fit thirteen-years-old human. In this story she has kryptonian DNA with all it entails: she is super-strong, faster than a speeding bullet, nearly invulnerable... and she can fight giant {{Eldritch Abomination}} with her bare fists.
* Many canon characters from ''Fanfic/YuYuGiDigiMoon'' have given power ups: such as the Digimon Tamers receiving beast powers base on the Four Chinese Symbols, and the Sailor Senshi receiving the mysterious Valkyrie forms.
* ''FanFic/JusticeLeagueOfEquestria'': ComicBook/{{Deathstroke}} has always been a skilled fighter in Franchise/TheDCU, but here he manages to get the drop on Rainbow Dash (this universe's equivalent to Franchise/{{Superman}}) in their first encounter, and then manages to almost defeat her again during their fight in Cloudsdale.
* ''Fanfic/ChildOfTheStorm'' has a number of these:
** Sean Cassidy goes from C-List X-Man (B-List on a good day), famous for screaming loudly and (somehow) flying, to a deadly spy with decades of experience and, thanks to a NoodleIncident, the physique of a man in his prime. And as he [[BodyHorror demonstrates]] on HYDRA troops, his abilities go far beyond simple screaming and he most definitely knows how to use them.
** [[spoiler:The Winter Soldier]] progresses from street level nightmare and DarthVaderClone to the terror of the entire Western World, an immortal wraith-like figure and OneManArmy who induces pants crapping levels of terror from just about anyone who hears of the possibility that he might be around. And he backs up the hype too: he's [[OneHitKill one shotted]] [[PhysicalGod a former Captain Britain]], for instance. In one of his rare on-screen appearances, he's killed [[spoiler:James Bond]] with minimal effort. And he killed Kennedy. Loki calls him possibly the most dangerous assassin in the Nine Realms, and it's kinda hard to argue with the guy.
*** In chapter 60 he shows what he's really capable of by ambushing [[ComicBook/CaptainAmerica Steve]], [[ComicBook/BlackWidow Natasha]] and [[ComicBook/{{Hawkeye}} Clint]] and having them dead to rights.
** Harry packs more magical power than in canon, growing into a fully fledged GuileHero who actually plans ahead to an extent, while remaining a master of the IndyPloy. He's also a lot more confident, to the point where he's more than willing to stand up to gods and monsters alike with absolutely no fear. Plus he's got [[spoiler:[[WindsOfDestinyChange Wanda's blessing]]]] at his back, which means that he's even more magnetic to potential hero types than before. And all of that aside, he's a Prince of Asgard whose powers are beginning to come through.
*** By chapter 70, he's a bona fide OneManArmy and PersonOfMassDestruction - though his technique needs work. He grows into a SuperSoldier and FlyingBrick in the sequel, [[HadToBeSharp which is just as well, considering how dangerous many of his opponents are]].
** Voldemort. Apparently, he went toe to toe with ''Magneto'' at one point when both were younger, as well as James Braddock at another. And on top of that, [[spoiler: he steals some of Harry's PsychicPowers]], which as the start of ''Ghosts of the Past'' shows has made him a thousand times more dangerous. And more dangerous even than that is the fact that this incarnation is a CombatPragmatist with no inclination towards the kind of BondVillainStupidity he showed in the books.
** In the MCU, Thor is a FlyingBrick with ShockAndAwe powers (though he admittedly starts to grow beyond this in ''Ragnarok''). In this version, he proves that he has roughly ''1500 years of experience,'' meaning that he can do far more with his powers than just throw around lightning or whip up cyclones, and even without Mjolnir, can still go hand-to-hand with the Juggernaut.
* On ''Fanfic/CoreLine'', this is the essential fate of anybody who enters the post-[[TheMultiverse multiversal]] RealityBleed WorldOfBadass of the setting. They all [[HadToBeSharp have to become sharp]], or risk dying (at worst). And as such, whenever any two characters of two differing fandoms clash (''any two''), it's up in the air who will win (if they are not cut down mid-fight by a BadassBystander who's had enough).
* ''FanFic/TheGoodTheBadAndTheDemon'' has [[WesternAnimation/TeenageMutantNinjaTurtles2012 April O'Neil]] and her best friend, [[VideoGame/SoulHackers Hitomi Tono]]. In the former's case, using more of her psychic abilities ever since [[spoiler:she found she's half-human, half-Kraang]], while the latter has learned to fight with April's help.
* ''Fanfic/WeissReacts'':
** Cardin went from vaguely wimpy JerkJock to badass GentleGiant who is considered TheDreaded.
** Blake now has the [[Anime/TengenToppaGurrenLagann Gurren Lagann]] at her beck and call. She also uses Spiral Energy in addition to Aura.
** Jaune is a lot less wimpy and a lot more savvy, capable of holding his own in a fight. Also, Nora now utilizes ConfusionFu and, in some chapters, borrows her mother's ''[[NoKillLikeOverkill rail]][[ShockAndAwe gun]].''
** [[spoiler:Tukson, who was killed in the first two minutes of Volume Two,]] is a master Huntsman and martial artist capable of taking on Team RWBY by himself here. Not only that, but he doesn't ''need'' weapons; he's a BareFistedMonk who uses KiAttacks.
** Over in ''Fanfic/LucinaReacts'', [[TheQuietOne Kellam]] is turned into TheAce, who matches the canonical Ace Cordelia for competence. This is a {{downplayed}} example in that Kellam was already a canonical badass, but much more understated and less focused on.
** In ''Fanfic/HomuraReacts'', Hitomi is turned from a rather average {{Ojou}} to a LadyOfWar capable of taking on Sayaka and Kyoko on a two-versus-one fight and win with her [[MegatonPunch bare fists.]]
* ''Fanfic/TheBridge'':
** Kaizer Ghidorah became an expert at close combat in addition to his already overwhelming strength and energy attacks.
** Anguirus is considerably stronger than in canon, having more abilities he didn't in cannon. The most telling factor is during Final Wars he fought the Simian Mechagodzilla, and while taking a beating, ultimately managed to destroy it whereas in canon he was curbstomped by it.
** While extremely powerful in the unused projects that would have featured him, [[spoiler:Bagan is a straight up PhysicalGod here.]]
** [[spoiler:G1 Grogar was a HeroKiller and one of the biggest threats in the series as it was, here? He's [[PhysicalGod as strong as Bagan and Harmony]] and thus powerful enough to ''[[CurbstompBattle curbstomp Grand King Ghidorah]]'' if they were to fight.]]
* Fanfic/PersonaEG: Flash Sentry, as the main character, is a Wild Card, is very good at playing Guitar, seems to be a ChickMagnet, and has gotten good at swinging a battle axe around. Not bad for a fairly minor character from the Equestria Girls movies.
* ''FanFic/PaperMarioX'' gives Malon archery skills and magic music power. The bosses are also much tougher to make the fights more interesting due to how many more characters they're fighting at once.
* ''[[http://fanfics.me/read2.php?id=127043 A RWBY Zanpakuto]]'':
** Ichigo Kurosaki has four zanpakutos, the weapons of Team RWBY, and access to his Hollow, Quincy, and Fullbringer powers during the Soul Society arc.
** Uryuu Ishida is much more creative in applying his powers, [[spoiler:and manages to kill Mayuri in a way that gains him his knowledge.]]
** Orihime Inoue is more willing to fight, and gains a limited teleportation.
** Chad actively trains with Yoruichi and becomes powerful enough to actually challenge Arrancars.
** Rukia becomes a Visored and gains her Bankai early.
** Tatsuki becomes a Fullbringer and becomes powerful enough to challenge Arrancars. [[spoiler:She's also the one who defeats Tsukishima.]]
** A Hollow's HealingFactor can repair damage to internal organs, while in canon it could not.
** Ulquiorra has an AdaptiveAbility.
** Aizen has a SwordBeam attack, actually uses his Bankai, and his final battle with Ichigo is much more impressive.
* While in canon, Foquet the Crumbling Dirt was skilled at making giant golems and [[CripplingOverspecialization not much else]], in ''[[https://www.fanfiction.net/s/11175004/8/ Star Wars Episode I: The Familiar of Zero]]'' she's a badass Square Class earth mage capable of matching a Sith in a sword fight. Her claim that fighting her "is to fight the earth itself" isn't an empty boast either as she can strengthen her body, create pits of quicksand, and conjure nigh indestructible adamantine golems. If Guiche's reaction is anything to go by, she's the earth mage equivalent of Karin the Heavy-Wind.
** Kirche is a dangerous melee combatant, using magic to conjure an axe and shield to fight with. She even manages to beat Louise who's not only wielding [[InfinityPlusOneSword Derflinger]] but has been studying under a Sith lord.
* ''[[https://www.fanfiction.net/s/12213237/1/Metroid-Kamen-Rider-Generations-Vol-2-Ex-Aid-Era-feat-Cross-Ange Metroid: Kamen Rider Generations Vol 2 - Ex-Aid Era feat Cross Ange]]'' takes it UpToEleven as [[Franchise/{{Metroid}} Samus]] becomes a Kamen Rider at her own right as Kamen Rider Huntress after [[Series/KamenRiderExAid Kuroto Dan]] gives her [[spoiler: a Mighty Action X SP Gashat and Gamer Driver.]]
* ''Fanfic/FairyWithoutWings'' does this simply because of its setting to the entire case of ''Anime/CodeGeass''. In addition, [[MsFanservice Jenny]] is a legitimately powerful mage, [[RoyalsWhoActuallyDoSomething Princess Hisui]] has shown she's not [[DamselInDistress Princess]] [[Videogame/SuperMarioBros Peach]], and the Rune Knights are now capable of fighting some of Fairy Tail's best with some of their best.
* ''Venus Flash'' does this to Hikaru Sorano: in ''Manga/CodenameSailorV'' she's merely Minako's {{Muggle}} best friend, but here it turns out she's actually an amnesiac [[spoiler:Anime/CuteyHoney]], and as soon as she remembers she becomes a force to be reckoned with.
* ''[[https://www.fanfiction.net/s/10448834/32/Six-Paths-of-Rebellion Six Paths of Rebellion]]'' makes a fair number of ''Anime/CodeGeass'' characters anywhere from slightly to immensely more badass than canon. While Kallen gets a Geass, Rakshata, Sayoko, Euphemia, and Nunnally all gain the [[Anime/{{Naruto}} Rinnegan]] and become one of C.C.'s [[TitleDrop Six Paths of Rebellion]]. While Rakshata uses hers to become an extraordinary healer, Euphemia and Nunnally both train to become fighters with Nunnally taking up the mantle of Infinity to act as Zero's protector.
* ''[[https://mega-poneo.deviantart.com/gallery/62840836/Tomica-Hero-Rescue-Pups Tomica Hero Rescue Pups]]'': ''Where do we start?'' The ''WesternAnimation/PawPatrol'' pups start by defeating several Axto when in their own show, the pups barely ever engage in combat. And this badassery only [[SerialEscalation escalates from there]], seeing that the author repeatedly has them reference ''Franchise/StarWars'' and ''VideoGame/{{Bayonetta}}''. Notably, Chase has a stun baton now while Skye gets a blaster and later a lightsaber. Then the pups begin to unlock their own sets of Force powers. Also applies to the Axto, since they now have lightsabers, blasters, TIE Fighters, [=AT-ATs=], and eventually Death Axto based on [[Film/RogueOne Death Troopers]].
* [[Anime/OnePiece Makino]] in ''[[https://www.fanfiction.net/s/12696961/2/Stallion-of-the-Line Stallion of the Line]]'' joins Luffy/[[Manga/RanmaOneHalf Ranma]] on his journey and due to training with both Luffy and Garp, knows Armament Haki.
* From ''Fanfic/DuelingTriggerFinger'': [[Anime/YuGiOh Rex Raptor]] gets to show just how competent of a duelist he is while dueling [[VisualNovel/{{Danganronpa}} Makoto]]. Even though Makoto wins, it was ''not'' easy.
** [[VisualNovel/{{Danganronpa}} Celeste]] was already competent to start with in canon, but here she's a freaking treat. Not only is she one of the more skilled duelists in the story, but she is putting that gambling talent of hers to work given her collusion with [[ArcVillain Marik]].
* Comicbook/BlackWidow in ''[[https://www.tthfanfic.org/Story-31969-2/Nycorson+Vacation+means+Chaos.htm Vacation means Chaos]]'' is much more dangerous than her movie self. Not only has she taken the same SuperSerum as Comicbook/CaptainAmerica, but she's also been an assassin since World War II, putting her more inline with her comic book self. [[Series/BuffyTheVampireSlayer Xander]] notes that even Buffy probably couldn't take her in a fight.
* In ''Manga/MyHeroAcademia'', the protagonist, Izuku, is a [[MuggleBornOfMages Quirkless]] boy who is gifted One for All, which grants him incredible SuperStrength that comes at the cost of wrecking the bones in whatever limb he used the power in. In ''[[FanFic/NeitherABirdNorAPlaneItsDeku Neither A Bird Nor A Plane Its Deku!]]'', he's a Kryptonian LightningBruiser with ComboPlatterPowers and NighInvulnerability. Do the math.

[[AC: ''Manga/DeathNote'']]
* Inverted in the AlternateUniverseFic, ''Fanfic/PointOfSuccession''. Light Yagami is BroughtDownToBadass-- there's no [[ArtifactOfDoom Death Note]], which means Kira doesn't exist in this universe, [[BroughtDownToBadass "reducing" Light]] to being simply a [[BadassBookworm genius]] [[TheProfiler criminal profiler]] and [[ImprobableAimingSkills a hell of a good shot]].

[[AC: ''Franchise/{{Digimon}}'']]
* In ''Anime/DigimonAdventure02'' [=MaloMyotismon=] is built up into a major threat only to be swiftly deafeated with in the [[AntiClimax most anti-climactic]] way possible by TalkingTheMonsterToDeath. ''FanFic/Zero2ARevision'' on the other hand, builds him up into a major threat thanks to all of his schemes and planning. His power is so great that even the TimeMaster Xeedmilleniummon and the [[PhysicalGod Guardian Beasts]] will fall before him. To defeat him, the Digidestined and their Digimons fused together and after a long and tough battle, in the end managed to defeat him.

[[AC: ''Franchise/DragonBall'']]
* In ''[[https://www.fanfiction.net/s/5189405/1/Dragonball-Divergence Dragonball Divergence]]'', Chi-Chi decides to keep training [[ForWantOfANail after having a conversation with Kami during her and Goku's wedding reception]]. As a result, she's a much more capable fighter than in canon, joining the Z Warriors and playing important roles in the defeats of several villains.
* Everyone in ''[[https://www.fanfiction.net/s/5390962/1/AU-A-Saiyan-Warrior AU: A Saiyan Warrior]]'' ends up stronger as a result of Bardock leaving a message in Kakarot's pod before he's sent to Earth. By the time Raditz arrives on Earth, Kakarot is roughly ten times as strong as Goku was in canon. Special mention goes to Krillin as he, not Kakarot, receives training under King Kai and thus becomes one of the Z Fighter's heavy hitters.

[[AC: ''LightNovel/TheFamiliarOfZero'']]
* Canonically, Saito was just a regular guy until he was chosen as Louise's familiar. However, in ''Fanfic/ZeroNoTsukaimaSaitoTheOnmyoji'', he was already a fully-accredited mage, and being summoned to Halkegenia only made his powers greater.

[[AC: ''VideoGame/FinalFantasyVII'']]
* Kunsel is a normal [[SuperSoldier Second Class]] with being a well informed and vaguely gossipy MrExposition as his distinguishing trait and doesn't stand out in a company with the likes of Sephiroth and Zack Fair. In the ''FanFic/TheFifthAct'', he is shown to match [[TheAce Zack]] in skill when given the motivation and to be far more perceptive and knowledgeable than people realize. Kunsel is upgraded to being a powerful KnowledgeBroker having a vast information network, being everyone's go to guy for information and in the Omakes, being better informed than the Turks.

[[AC: ''Manga/FruitsBasket'']]
* In one apparently non-[=AU=] [[https://www.fanfiction.net/s/9458466/8/Tohru-s-an-Animal-Element fic]], [[AllLovingHero Tohru]] is a respected mob boss and cold-blooded killer, for some reason.

%% [[AC: ''Website/ThatGuyWithTheGlasses'']]
%% Needs more context
%%* Possibly the entire cast of ''Fanfic/ThatGuyWithTheGlassesInSpace''.

[[AC: ''Franchise/HarryPotter]]''
* ''Fanfic/HarryPotterAndTheMethodsOfRationality'':
** [[ProperlyParanoid Severus]] [[CrazyPrepared Snape]] has been spiking Lord Voldemort's father's grave with every dangerous drug and poison known to wizardkind (and LSD--because it ''might'' affect him), as well as every other grave in the cemetery on account of Voldemort might have moved the gravestone, ''and'' the graves of every other ancestor of Voldemort's that he and Dumbledore could track down, ''just in case''. [[OutGambitted Too bad]] [[MagnificentBastard Voldemort]] foresaw this contingency and, since he couldn't move his father's bones if he wants the resurrection spell to work, moved ''the entire rest of the cemetery'' to an entirely different location and memory-charmed the local Muggles.
** Harry Potter, in so many ways. Here's his following plan:
-->"Note to self: [[WellIntentionedExtremist overthrow government of Magical Britain at earliest convenience]]."
** Draco Malfoy went from TheBully to ManipulativeBastard, TheStarscream to Harry, and scion of a long, proud line of [[TheManBehindTheMan Men Behind the Man]].
** Quirrell in canon is a simpering stutterer who's [[spoiler:a host to Voldemort]]. WordOfGod says this Quirrell is possessed by Voldemort, which now makes him an EvilMentor to Harry, a sixth-''dan'' in an unspecified martial art, and he horcruxed the pioneer probe! Oh, and then he went and tricked Harry into [[spoiler:breaking Bellatrix Lestrange out of Azkaban]].
** [[ChronicBackstabbingDisorder Blaise Zabini]] went from Draco's crony to a ''quin''tupple agent in a war with only three sides.
* ''Fanfic/CruciamentumEternus'' includes Lucius Malfoy during the time period of the last book. In the canon he was broken, pathetic, weak, and didn't fight Voldemort until it was safe to (and Narcissa pushed him). In this story, Draco's murder has him secretly murdering Death Eaters from almost the moment he's released from Azkaban, while still feigning allegiance to Voldemort's side, with the ultimate plan of killing Voldemort himself. If nothing else that requires at least an epic feat of Occlumency and a strength of will he never shows in the books.

%%Context needed:
%%[[AC: ''LightNovel/InfiniteStratos'']]
%%* [[CluelessChickMagnet Ichika Orimura]] in ''LightNovel/InfiniteStratos'' is TheScrappy, mostly due to being [[ObliviousToLove dense as brick]] and has [[UselessProtagonist a long]] list of InformedAbility. When fans start tampering with him, we get the following:
%%** ''Fanfic/InfiniteStratosSacredTwins'' Ichika that's
%%** ''[[http://www.fanfiction.net/s/7597864/1/Infinite_Stratos_Resolve Infinite Stratos Resolve]'' actually smart
%%** ''[[http://www.fanfiction.net/s/7405918/1/Second_Chance Second Chance]]'' Ichika fusing with
%%** ''[[http://www.fanfiction.net/s/7505068/1/The_fusion The Fusion]]'' his I.S.
%%** ''[[http://www.fanfiction.net/s/7522787/1/Soaring_of_the_Doukugan_Ryu_Orimura_Ichika Soaring of the Doukugan Ryu Orimura Ichika]]'' Ichika that clogging too much testosterone

[[AC: WesternAnimation/JackieChanAdventures]]
* FanFic/ProjectDarkJade:
** ''FanFic/QueenOfAllOni'' has the Samurai Khan. While in canon they're {{Fake Ultimate Mook}}s, here they're just as strong as they look, serving more as EliteMooks.
** In ''FanFic/{{Webwork}}'' the Samurai Khan get the same treatment, with a WorfHadTheFlu explanation: their General wasn't properly bonded to his host, halving the Samurai Khan's power. They were also being poorly managed.

[[AC: ''Series/KamenRiderFourze'']]
* In ''Fanfic/{{Horseshoes and Hand Grenades}}'', nearly every single character who ever appeared in ''Series/KamenRiderFourze'' have gone into fighting mode. This ranges from [[{{Otaku}} Yuki Jojima]] using her Hayabusa Plushie as a boxing glove, [[ButtMonkey Chuta Ohsugi]] fighting off his former love interest, Sarina Sonada and minor characters like the ones in the Amanogawa High Glee Club consist of a sword wielder, a samurai and a ninja.

[[AC: ''Franchise/KingdomHearts'']]
* The Princesses of Heart in ''[[https://www.fanfiction.net/s/1048901/42/Stygian-Solace Stygian Solace]]''. [[SilkHidingSteel Snow White]] can hold her dying world together with sheer force of will despite being the only human survivor and all of them together can force ''[[BigBad Id]]'' and Maleficent through a HeartBeatDown and their powerful light magic. Kairi unintentionally can [[CreatingLifeIsUnforeseen create life]] [[spoiler: as seen with Yami.]]

[[AC: ''WesternAnimation/TheLegendOfKorra'']]
* While Korra was undoubtedly badass in canon, she is even more so in ''FanFic/TheSagaOfAvatarKorra'', accomplishing or gaining abilities sooner than her canon counterpart due to being raised and put through a TrainingFromHell regiment by the Red Lotus for fourteen years, and delivering {{Curb Stomp Battle}}s to characters who were more difficult for her to defeat in canon, such as Unalaq, Desna, Eska, and Kuvira.

[[AC: ''Manga/LoveHina'']]
* ''FanFic/ContractLabor'': In direct contrast to the ExtremeDoormat he was in canon, Keitaro actually has some backbone and is far more willing to stand up to and for the Hinata's residents, even managing to defeat Motoko in an honor duel.
* In ''[[https://www.fanfiction.net/s/9305815/1/The-Merry-Killers The Merry Killers]]'' every girl at the Hinata Sou from Haruka to Shinobu is a skilled assassin. Even Kitsune, who specializes in organizing and managing their hits, manages to hold her own against [[Manga/Golgo13 Golgo]]. While Keitaro isn't an assassin or even really a fighter, he's still NighInvulnerable, even shrugging off JumpingOnAGrenade and being annoyed at most upon being hit by a sniper round.

[[AC: ''Franchise/LyricalNanoha'']]
* ''Fanfic/GameTheoryFanFic'':
** [[MonsterOfTheWeek The Jewel Seeds]] get a serious upgrade in their power and threat level. As the author explains:
-->'''Aleph:''' Nanoha showed us that the Monsters of the Week could be a backdrop to the real meat of the plot, the character interaction, but then [[Anime/PuellaMagiMadokaMagica Madoka]] came along and showed us that the Monsters can still be legitimately, vividly scary. And Game Theory is very much a post-Madoka story, with the harsher rules and the scarier monsters and so on.
** Pretty much all the characters over the age of about sixteen or so get a significant competence boost. They aren't any more powerful[[note]]At least at first. During the sequel, it's shown that Alicia far greater magical power and understanding than her canon counterpart did, on account of her revival being accomplished by essentially merging her with a Jewel Seed. And when Raising Heart and Bardiche get damaged fighting the Wolkenritter, Alicia upgrades them with ''[[ArtifactOfDoom Jewel Seeds]]'' instead of the cartridge system, giving Nanoha and Fate access to potentially similar boosts...though she restricts the amount of the Seeds' power that can be accessed as a safety measure.[[/note]], but they use what they have ''much'' more effectively because they employ proper tactics, especially Precia (since the entire premise of the story is that she's only ''slightly'' insane instead of full-blown bonkers). The Wolkenritter in particular have received a major upgrade in skill, showing the experience and tactical acumen that would be expected of centuries old combat constructs.

[[AC: ''Anime/MaiHime'']]
* Yukino in ''Fanfic/PerfectionIsOverrated''. In the original series, her Child was only good for surveillance, and left her easily defeated by Shizuru. In this fic, she realizes that while she's not the best in a straight-up fight, she can use her powers to tip the balance of power in her favor at crucial moments, such as when she [[spoiler:incapacitates Shiho, enabling Mai to win her battle without Yuuichi dying]], and when she, in the final battle, uses her Child's abilities to immobilize one of the last remaining [=SUEs=]' Child long enough for Natsuki to finish her off.

[[AC: ''Franchise/MarvelCinematicUniverse'']]
* In {{Creator/madsthenerdygirl}}'s ''Fanfic/MCURewrites'', Sharon Carter is given more focus that shows her to be a competent fighter. ''[[http://archiveofourown.org/works/11652534 Captain America: Ghosts of HYDRA]]'' has her accompany Steve Rogers in his mission to help Bucky Barnes and take down what's left of HYDRA. She mows down numerous HYDRA agents, gets into a fight with Brock Rumlow/Crossbones, [[spoiler:and takes on [[SuperSoldier Winter Solder Josef]] and comes out on top by [[BoomHeadshot shooting him in the face]].]] In ''[[http://archiveofourown.org/works/11652651 Avengers: Civil War]]'', [[spoiler:she helps Maria Hill bust Scott Lang, Clint Barton, and Sam Wilson out of the Raft Prison and blow it up.]]

[[AC: Franchise/MarvelUniverse]]
* This trope is a staple for the villains of ''FanFic/UltimateSleepwalker: The New Dreams'' and ''FanFic/UltimateSpiderWoman: Change With The Light''. Characters like 8-Ball, the Brothers Grimm, the Chain Gang and Jack O'Lantern were all C-lister villains, at best, in the original comics. In the Earth-2706 verse, though, they're exceptionally deadly threats, forming the focus of the Fics.

* ''Fanfic/RiseOfPaonneAndRenardRouge'': Because [[spoiler:Gabriel is an experienced RetiredBadass hero in this continuity]], the Collector is a much bigger threat. Ontop of having fighting experience, his legitimate corruption (as opposed to simply acting like a victim of akumatization like in-canon) means that he does not hold back, making him a super-effective fighter against all four heroes. Hawk Moth even remarks that he might be one of the best villains he has created given his effectiveness. It takes the combined efforts of Paonne, Chat Noir [[spoiler:and what was left of the original Quantic Team]] to take him down.

[[AC: ''Franchise/MyLittlePony'']]
* [[https://www.fimfiction.net/story/341014/duelists-of-the-autumn-crown Duelists of the Autumn Crown]] has Flash Sentry. While we don't know how skilled he was in the movie, there he's the best duelist in the school second only to Sunset Shimmer, and with her there are light implications that she's cheating somehow.
* ''Fanfic/PonyPOVSeries'':
** Mimic is said by Princess Luna to have been the first, and only, mortal pony to injure Discord, by ''kicking him in the face at supersonic speeds'' until she knocked his tooth out. He killed her afterwards, but still. [[spoiler:Starsong probably also counts, managing to fend off Discord's brother Anarchy for a considerable time.]]
** While Princess Cadence turned out to be pretty badass in canon, the version of her in this series was able to [[spoiler:take on an avatar of Discord's father [[EldritchAbomination Havoc]] and not only survive, but it's implied that she ''won''.]]
** There's also the CMC, who manage to be BadassAdorable in this universe, Minuette and Twinkle Shine, who ''really'' get to show off their Gifted Unicorn credentials, Shining Armor, who [[spoiler:''saved the world'' from an Imagination Demon]], and Trixie [[spoiler:who becomes the SixthRanger and grows to be able to fight Twilight on fairly even standing (though played with in that regard: she at first ''avoids'' and ''fights'' her Element of Magic because she hates the idea of being 'back up Twilight' until she eventually realizes she represents magic in a completely different way).]] Honestly it's easier to count the characters that ''don't'' count.
* ''Fanfic/RainboomsAndRoyalty'' has Zecora, while still being the mentor to the Mane Six like in canon, also proved personally fantastic repeatedly over the course of the series, with such highlights as [[spoiler:saving Rainbow Dash from the Shadowbolts, fighting Nightmare Moon one-on-one, and saving Dinky, Pipsqueak, and Alula from King Sombra's bushwoolie {{Mooks}}.]]
* ''Fanfic/{{Xenophilia}}'' turns [[RecurringExtra Lyra Heartstrings]] into a grandmaster of the Still Way, the only Unicorn-exclusive martial art. She's described by Rainbow Dash as "probably one of the five or six most dangerous ponies in Equestria, even counting the Princesses," and the only pony in town other than Twilight who could beat her in a serious fight. Chapter 9 reveals her to be [[spoiler:an auxiliary Royal Guard, and we also see her in action.]]
-->'''Lero''': Wow. I had no idea. She's always been really friendly to me.\\
'''Rainbow Dash''': ''[giggling]'' Yeah, Iíve heard that about her. ''Total'' sweetheart, youíd never guess that she could kill you in half a second from, like, three hundred bodylengths away.
* Rarity is slowly heading in this direction within the ''FanFic/TriptychContinuum'', and it comes from recognizing her own limitations. She has strictly average [[InsistentTerminology field]] strength, knows ''no'' spells for direct offense or defense, her physical abilities are nothing special -- and she's been placed in a position where she regularly has to risk her life in direct combat. So how is she dealing with this? [[CombatPragmatist Through becoming the single dirtiest fighter anypony's ever seen.]] Take a telekinetic with exceptionally fine directional control who regularly carries sewing needles with her, then pray she doesn't have a straight shot at your eyes. And in physical combat, she'll go for joints, sensory organs, vulnerable spots, and everything else offered without caring about dignity or the pain of the other party, because all that pales in significance to her goal of coming out alive. Compared to the others, she may not bring much to bear -- but what she does have is targeted with terrifying efficiency.
* Cadence in canon, while admittedly having some badass moments, is still mainly a supporting character. On the other hand, Cadence from the ''FanFic/BloomingMoonChronicles'' has wanted to be a soldier ever since she was young, rather than sit back and be a princess. Over the course of the series, she eventually grows more proficient at fighting, being able to utilize both weapons and magic to her advantage. She becomes part of the Orphans, an elite fighting force that keeps [[TheMultiverse the worlds]] safe from threats. At one point, she takes on [[spoiler: [[BigBad Loki]] himself]], and is capable of going head-to-head with some of his strongest forces.
* In the ''Fanfic/HarmonyAndValor'' series, Flash Sentry and Sweetie Drops are martial art masters who are strong enough to toss thugs around like ragdolls.

[[AC: ''Franchise/{{Naruto}}'']]
* In ''{{FanFic/Vapors}}'' because she was found by the Third Hokage and adopted into the [[BadassFamily Uzumaki Clan]] as well as studying under [[BloodKnight Anko,]] Karin here is capable of holding her own with [[TheAce Sasuke]] in combat and is often paired with him on missions.
** In canon Konan got caught by Jiraiya, acted as support during Painís attack on Konoha, and got killed by Tobi. Here she demonstrates exactly why she’s TheDragon.
* In canon, [[BigBad Kaguya]] is a joke, an AntiClimaxBoss that was defeated by Narutoís Reverse Harem Jutsu. In ''[[FanFic/BlackkatsReverse Reverse]]'', however, Kaguya is the HeroKiller and caused the extinction of the human race and Kuramaís plan boils down to [[PeggySue preventing]] her from awakening.
* ''Fanfic/SonOfTheSannin'' does this to Naruto and his peers, and with a justified reason in-story: [[spoiler: as a result of the Uchiha clan's uprising]], Konoha suffers a major blow to its military manpower, and thus they're forced to up the standards in the ninja academy to ensure that the graduates are better prepared to handle future threats. This includes teaching them chakra control, [[ElementalPowers elemental]] and medical ninjutsu.

[[AC: ''Anime/NeonGenesisEvangelion'']]
* ''Manga/{{Evangelion 303}}'': Several characters are more badass than their canon counterparts:
** Shinji is an adult, seasoned soldier in contrast to his untrained teen pilot canon self.
** Touji, Hikari and Kensuke are jet fighter pilots rather than average teenagers.
* ''Fanfic/NeonGenesisEvangelionGenocide'' turned Asuka into a greater badass than her canon self. After recovering from her breakdown, she kills most of giant alien monsters that try to mess with her.
* In ''Fanfic/NobodyDies'' Kei Ayanami was originally just another one of [[QuirkyMiniBossSquad The Ree]] with BondVillainStupidity as her Quirk. And then [[RecursiveFanfiction The Kei-Files]] came out, and she was changed into a {{Manipulative|Bastard}} [[JerkassWoobie Woobiefied]] badass girl with {{Adorkable}} and [[BrokenBird Fragile]] traits, making her one of the most [[EnsembleDarkHorse beloved]] original characters of the fic.

* In ''[[https://www.fanfiction.net/s/11920014/5/ Logia Luffy: Rise of the Dark Emperor]]'', Kuro is given a Zoan Devil Fruit, mostly to keep his fight with Luffy from being too one sided.
* In ''FanFic/ThisBites'', [[spoiler:Hattori]] is actually a dangerous assassin capable of using the Six Powers.
** Several of the Straw Hats become stronger sooner due to Cross giving them hints regarding their future abilities. Special note goes to Chopper who develops a JekyllAndHyde personality and creates his own explosives, earning himself a 66 million bounty, and Nami who gained [[spoiler:Ohm's Eisen Dial]] and ''fried ten battleships'' at Enies Lobby, making her a Supernova with a bounty of 125 million.
* Miss Valentine in ''[[https://www.fanfiction.net/s/11137293/21/One-Piece-Truly-Precious Truly Precious]]'' has some level of ability with Armaments Haki, making her considerably more dangerous than canon.

* [[ZigZaggingTrope Zig-zagged]] in ''[[https://www.fanfiction.net/s/11725053/1/The-Bald-and-The-Esper The Bald and the Esper]]'' as Tatsumaki starts off weaker than canon but with far more varied skills (using her telekinesis to create bombs, laser blades, and more) then starts training under Saitama. By the Sea Folk Arc, she's learned how to turn someone's energy against them. While against Saitama, it only nudges his fingers, against a monster, it spins them with so much force they rip apart.
** The Sea King is also more dangerous to counter Tatsumaki's different skill set from Genos. Here, he can split into three equally powerful bodies to overwhelm enemies or act as distractions.

* In canon, Kousaka Kyousuke is the type of person who lets [[{{Tsundere}} his sister]] walk all over him. Contrast this to ''[[http://www.fanfiction.net/s/7330418/1/My_Life_Cant_Lose_Its_Normality My Life Can't Lose Its Normality]]'' where he (as well as Ayase, Akagi, and Miura) are a team of martial-arts mastering, {{Yakuza}}-killing vigilantes who pull off stunts normally reserved for paramilitary organizations and special operatives.

[[AC: ''VideoGame/Persona5'']]
* In the game, Shiho was a victim of [[EvilTeacher Kamoshida's]] physical abuse and implied sexual harassment, to the point where she [[DrivenToSuicide attempted suicide]]. in ''Fanfic/TheEvilQueen'', [[ForWantOfANail where Kamoshida was ousted before things got that bad]], Shiho is a much stronger individual to the point where [[spoiler:she becomes a Persona user]].

[[AC: ''Franchise/{{Pokemon}}'']]
* In canon, Ash Ketchum is a rather bumbling, childish, and well...stupid, trainer. In ''FanFic/TheChosenOnesJourney'', all that is replaced with maturity, responsibility, discipline, and pure badass.
* Due to the result of a PeggySue plot, ''Fanfic/AshesOfThePast'' has pretty much ''everyone'' that Ash has come into contact with become a bona-fide badass. This ranges from Ash actively pursuing his Aura Guardian training and fighting Pokémon with his bare-hands, to Charizard learning the Poké-equivalent of a ''tactical nuke'', to Squirtle (as a now-[[Anime/TengenToppaGurrenLagann Kamina]] expy) breaking the laws of physics on a regular basis.
* {{Fanfic/Traveler}} does this pretty much across the board. Of note is Ash himself, who goes from headstrong and clueless in the anime to a more calm and collected battler who makes it all the way to the finals of his first Pokemon League, and shortly thereafter accepts a position as an Elite Four trainee.
** More than anyone though, the biggest jumps in badass come from the legendaries. Rather than OlympusMons that are powerful but can be beaten and even captured by the right strategy, or even just a strong enough opponent, in Traveler, the legendaries are just that, ''legends'': uncontrollable forces of nature that can impact whole nations by their mere presence, and whose full power can permanently change the shape of the world.
* ''Fanfic/PokemonResetBloodlines'' has this a lot. Bar the characters who have the titular bloodlines and the badass gains from such abilities, a wide variety of characters are much more impressive than their canon selves: The Team Rocket Trio can actually steal Pokemon, Georgia is a militarily trained Dragon Buster whose job it is to arrest corrupt gym leaders and elite four members, Ash's Pokemon evolve earlier and have new, more powerful moves they lacked in canon like Aerial Ace, Brine, and Zap Cannon, and Mabel from the XY anime went from granny to Lumiose Conference winning granny. Badassery isn't even just in physical power: Erika is shown to have sizeable monetary and political power she has never been shown to have in other canons.
* ''Fanfic/CommonSense'' is based on a simple premise: what if the TR Trio was actually competent? The answer: this trope. For bonus points, in response to this additional pressure, the "twerps" and their Pokémon are also more formidable than in canon.
* Both ''[[https://www.fanfiction.net/s/12803123/1/Shudo-cross-Modern-Ash-The-Trainer-who-Questions-Humanity Shudo cross Modern Ash: The Trainer who Questions Humanity]]'' and ''[[https://www.fanfiction.net/s/12840662/1/Shudo-cross-Modern-Ash-The-Professor-Who-Observes-his-Charges Shudo cross Modern Ash: The Professor Who Observes his Charges]]'' have an Ash with more evolved Pokemon and farther placement in the leagues he entered.

[[AC: ''Manga/RanmaOneHalf'']]
* ''Fanfic/RanmaSaotomeChiMaster'' has the title character arrive to Nerima with greater strength and skill, and an excellent understanding of Chi to boot. Moreover, under his tutelage, Akane [[TookALevelInBadass becomes increasingly formidable]].

[[AC: ''WebAnimation/{{RWBY}}'']]
* ''FanFic/RWBYReckoning'' takes the normally bumbling Jaune Arc, a guy who is nothing like his legendary ancestors, and makes him able to build a functioning time bomb with approximately 18 flares, some duct tape, and some scraps. And it's powerful enough to shred the stomach of a very large Grimm.
* ''FanFic/TheCommission'' takes the formidable, but still in training, girls of Team RWBY and makes them TheDreaded. They're the leaders of each of their groups, all acquired via hostile takeovers, and are engaged in their own [[TheConspiracy conspiracy]] with such ruthlessness and efficiency that scares the original show's vilains. Heck, those villains appear in this fic as the girls' subordinates.

[[AC: ''Franchise/SailorMoon'']]
* ''Fanfic/CosmicWarriors'' takes the normally cheesy Tuxedo Mask and has him [[CaneFu wielding his cane like a real weapon]] with [[SwordCane a hidden sword within]]. On top of that, his cane seems capable of more tricks, like shooting five rechargeable red thorn darts from the base.
%%* ''Fanfic/BeautifulDestroyerSailorMoon.'' Pick a main character, ''any main chracter.''
* ''Sailor Moon: Legends of Lightstorm'':
** Sailor Moon now fights primarily with sonic screams powerful enough to annihilate buildings, her energy disk can slice through almost anything, and her physical strength is great enough to punch through ''rocket-proof'' armor.
** Sailor Mercury impales things on gigantic ice spears and can stand up to the toughest of Negaverse drones single-handedly.
** Tuxedo Mask has fighting skills that rival Lightstorm's can cut through virtually any substance with his razor-roses, hits hard enough to knock gigantic drones off their feet, and can withstand explosions strong enough to shred drone armor.

[[AC: ''Franchise/SonicTheHedgehog'']]
* ''FanFic/SonicXDarkChaos'':
** Tails goes from being a weak, shy GadgeteerGenius into a MagnificentBastard captain who gains a LovecraftianSuperpower [[spoiler:and ends up saving the entire universe from an EldritchAbomination at the cost of his own life]].
** Cream stays with Sonic and friends to the end, even after seeing things that would make most adults break down. In Episode 66, she and her chao Cheese ends up beating Astorath the Prince of Darkness on her own.
** Cosmo saves several planets before becoming acting captain of the Blue Typhoon, and she is also appointed leader of the Metarex during the final battle. And in the rewrite, when Astorath and Beelzebub land on her ship, ''she runs out onto the flight deck with Venus' demon scythe and rips them a new one.''
** Chris Thorndyke goes from being a whiny, dependent brat to a GeniusBruiser, pulls off a BigDamnHeroes and unleashes DeathFromAbove with the Typhoon in the rewrite of Episode 69, and later on fights Beelzebub and Astorath alongside Cosmo during the final battle.

[[AC: ''Manga/SoulEater'']]
* ''FanFic/SoulEaterTroubledSouls'': An increasing number of canon characters show more skill or competency than their original counterparts, which is saying something. They are even gifted more techniques and moves than normal, especially those who lacked them. Here are some specific examples:
** This fic plays up Tsubakiís abilities as a ninja or assassin. She also seems to be a bit more resourceful.
** In canon, Ox has a pretty limited repertoire of techniques and moves. Here, he has plenty to spare, up to and including a Soul Resonance between him and Harvar.
** Crona receives stronger forms, learns Soul Resonance, can fight Medusa on equal or better footing, overcomes Mad Blood, and is saner. Oh, also, "badass" as in [[spoiler: kills Medusa ''permanently'']]!
** Kim fends off ''Medusa Gorgon'' long enough until The Cavalry comes ''without'' her Regeneration Magic.
** The Mizunes, specifically their fully combined form. In the original manga, that form of Mizuna is only seen in a fanservice cat fight with Blair. Here, this is the sisters' most powerful form, and they [[CurbStompBattle absolutely]] ''[[NoHoldsBarredBeatdown destroy]]'' [[BackToBackBadasses Caius and Tsuji]] in the Cobra Island arc.

[[AC: ''Franchise/SuperMarioBros'']]
* Cackletta wasn't really much of a threat in ''VideoGame/MarioAndLuigiSuperstarSaga'', being an unimpressive mage with an easy boss fight halfway through her game. In ''Fanfic/ClashOfTheElements'', on the other hand, she's a ManipulativeBastard of the highest degree, a [[spoiler:two-thousand year old remnant of the Dark King's forces who caused the legend of the [[VideoGame/PaperMarioTheThousandYearDoor Shadow Queen]] just to extend her own life]], and a [[TheChessmaster Chessmaster]] who successfully managed to outwit {{Big Good}}s. Implications exist to suggest she has also been able to control [[VideoGame/KingdomHearts the Heartless]].

[[AC: ''WesternAnimation/SuperWhy'']]
* The original Super Readers don't even fight against their enemies and for the most part either talk to the villains to [[EasyEvangelism join their side]] or run away if things get dangerous. Super Readers in ''FanFic/SuperReadersBiggestAdventure'' receive [[MidSeasonUpgrade power upgrades]] and proceed to kick the butts of the [[DemonicPossession possessed citizens of Storybrook]], as well as the [[BigBad Evil Reader]] and [[TheDragon Lexicon]]'s. Special mention goes to Alpha Pig and Wonder Red, since both [[TookALevelInBadass went up a couple of levels]], but as of Chapter 20 [[spoiler:Super Why has one upped them]].

[[AC: ''LightNovel/SwordArtOnline'']]
* In ''FanFic/TheKiritaChronicles'' Kirita, the {{Gender Flip}}ped version of Kirito, is more capable of being able to defend herself in the real world than he could. After quitting Kendo, she took up karate classes and is capable of delivering curb stomp battles to bullies and her fellow karate students. In canon, it is assumed Kirito focused solely on computers and video games. After being trapped in the video game, Kirita trains even harder to become stronger because she believes players will consider her vulnerable if they find out she is a female player.

[[AC: ''Anime/TengenToppaGurrenLagann'']]
* [[EmotionlessGirl Nia]] in ''Fanfic/TengenToppaGurrenSolvernia'', gets an upgrade through character development, since now it's she who's [[BigBrotherMentor mentored by Kamina]]. Simon, or rather, [[spoiler: Prince Simon Teppelin]] already starts as a badass, taking on a ganman with only a sword.

[[AC: ''VideoGame/{{Touhou}}'']]
* Rumia is lowest of the low in Gensokyo's hierarchy, weak and with [[WhatKindOfLamePowerIsHeartAnyway a useless power]]. It's widely speculated however that she possesses a SuperpoweredEvilSide, meaning most fan works featuring her give her an appropriate power boost, though the degree of the boost varies vastly; ''Fanfic/ImperfectMetamorphosis'' for example makes her into a WalkingWasteland and [[spoiler:a FallenAngel]], whereas in ''Webcomic/TouhouNekokayou'' she's slightly more powerful but ''still'' comic relief.
* Cirno, another canonically weak boss who is a [[EnsembleDarkhorse fan favorite]] due to AwesomeEgo, also gets this treatment quite often whenever she's not the MemeticLoser instead. [[http://i571.photobucket.com/albums/ss151/SuperFush/badasscirno.jpg Does this look like a stage 2 boss to you?]]
* ''Fanfic/ImperfectMetamorphosis'':
** Kotohime was a generally ineffectual and totally delusional combatant in her original appearance. In this Fic, she's graduated to the rank of BeleagueredAssistant to Yukari herself, running Gensokyo's first police force, and at one point she delivers a beatdown to [[PersonOfMassDestruction Marisa Kirisame]] for disintegrating one of her officers ([[FromASingleCell she got better]]).
** Yuuka Kazami in canon is certainly powerful and has aspects of TheDreaded, but there are plenty of characters who could take her in a fight. Yuuka in ''IM'' is the most feared being in Gensokyo's history, a nightmare who no-one dares confront directly, and who shrugs off all the attacks leveled at her by Yukari and her team she assembled specifically to kill Yuuka, in the process revealing her nature [[spoiler:as an [[Franchise/CthulhuMythos Outer God]]]].
* Mokou is already an immortal powerhouse and [[BonusBoss EX-Boss]]. ''Fanfic/TouhouIbunshu'' in addition has her possess the powers of a PhysicalGod, giving her the strength to go toe-to-toe with Yukari ''after'' creating an army of thousands of [[OurZombiesAreDifferent kashoyo]].
* ''FanFic/MaidensIllusionaryFuneral'' takes Yukari and Ran, already ancient sages with near-unsurpassed abilities, and makes them both TheJuggernaut who cleave through groups of specialist youkai hunters without a scratch. This in turn makes Yuyuko one as well, given she nearly killed Yukari while still trying to restrain her powers.

[[AC: ''VideoGame/{{Undertale}}'']]

* In the fanfic [[https://www.fanfiction.net/s/12126095/1/Recursion Recursion]], the normal FinalBoss of the Genocide run, [[CrouchingMoronHiddenBadass Sans]], is actually one of the first bosses [[SympatheticMurderer Frisk]] has to fight. The character that takes his place as the last and most difficult challenge before Asgore? It's ''[[TheQuietOne Napstablook]]'', who, after hearing about both of their cousins Mettaton and Furlablook dying, decides to fight... and gives Frisk a battle that puts Sans to shame.
--> '''Chara:''' (After seeing Napstablook's opening attack) ''"[[StunnedSilence I, uh... wow]]. I knew Napstablook before. [[BewareTheQuietOnes Didn't know they... uh, had it in them.]]"''
--> '''Frisk:''' "[[ThisIsGonnaSuck This is going to be Sans all over again, isn't it]]?"
** For starters, Napstablook's ''opening move'' is to transport Frisk into the space that you see during your time in his house... a massive ''intergalactic space'' not connected to Earth, [[StatingTheSimpleSolution where they decide to leave Frisk at first to die of starvation and/or thirst]]. When Frisk gets them to start fighting, however, Napstablook brings out a massive mix of mechanics from his fight, Sans's, and Mettaton's to give [[WellIntentionedExtremist Frisk]] [[ItMakesSenseInContext and Chara]] a ''very'' bad time...
** When the fight begins, Napstablook uses his own version of the Gaster Blasters: magical speakers that blast out sound waves.
** When Frisk manages to survive that, there are mini-Napstablooks akin to the mini-Mettaton's found in the battle with Mettaton EX (which, due to Frisk lacking a yellow soul, can't be targeted and destroyed) that fire musical notes and attack in tandem.
** Napstablook also has the "not really feeling up to it right now" words from his Pacifist fight. Which they use to sucker-punch Frisk when he tries to catch his breath by rushing him with acid tears.
** To top this, there's a "copy" mechanic that saves the positions of Napstablook's attack's at a certain time... which he combines afterwards with a ''paste'' mechanic. As in, ''[[OhCrap pasting the attacks he had when he copied onto the field in addition to the attacks already taking place.]]''
** After a while, Napstablook unveils a unique soul-affecting mechanic; a "soul tether", that makes Frisk to stay within a certain area or be yanked back into it forcibly, which they can also use to ''drag Frisk into the paths of their attacks.'' Later on, it turns out that they can tie Frisk to ''two'' different soul tethers, restricting his field of movement even further.
** And the two scariest parts about all this? First, Napstablook is a ghost, and can't be hurt without magic, [[NoSell which Frisk doesn't have]], meaning Frisk has to find a way to demotivate Napstablook enough to get them to leave. And second, Napstablook admits during the battle that they're out of practice. [[spoiler:And then it turns out the fight has a '''TimeLimit'''; when they decide that they've warmed up enough, Napstablook makes '''four''' soul tethers, forcibly anchors Frisk down with them, and blasts him with speakers until he dies]].

[[AC: ''Videogame/TheWalkingDead'']]
* ''FanFic/OldScars'' takes Sarah, one of the biggest liabilities in the game, and makes her more independent and self-aware, which allows her [[TookALevelInBadass Take A Level In Badass]] and become more capable and emotionally stable than her video game counterpart.

[[AC: ''Literature/{{Worldwar}}'']]
* In ''FanFic/WorldwarWarOfEquals'', all of South America, Central America, and Eastern Europe put up much more of a fight than they did in the source material. Human tanks qualify as well. In the original novels, even the best Human tanks of the 1940s could easily be destroyed by a single [[TankGoodness Landcruiser]]. Thanks to tank technology advancing in the last couple of decades, our tanks are either equal to or superior to their Landcruisers.

* ''Fanfic/{{Quicken}}'': In the original story, Emma was a powerless, cowardly girl. Here sheís a regenerator super-human capable of detecting other super-humans and stealing their powers and memories after killing them, and prone to go berserker.

[[AC: ''WesternAnimation/YoungJustice'']]
* In ''Fanfic/YoungJusticeTitans'', the Scarecrow gets a serious badass bump. Thanks to becoming a member of the Church of Blood, he's given supernatural powers, and is hinted at being essentially a real living scarecrow now, with impossible flexibility, his Sythe that he pulls out of his [[BodyHorror mouth]], and fear gas in both Gas and solid forms. He's even able to fight a team with powers far beyond him (including a Green Lantern). He's also almost unkillable too.
* Following in Young Justice tradition, Onomatopoeia in ''FanFic/WithThisRing''. In the comics, a guy with a gimmick. Here? A powerful magic user that uses onomatopoeia as the incantations for his spells.
** And also Dark Druid. In comics, he was a villain from the U.K. and thus barely even mentioned. Here, there are hints at him being a [[spoiler:herald of the Black Lantern Corps]].