A Lamb In Hell: Years to hone his divine abilities makes The Lamb about as dangerous as The One Who Waits used to be, with abilities including hypnosis immunity, full at-will access to the Crown's arsenal of weapons, curses, and his fleeces, and a One-Winged Angel form similar to those of Narinder and the Bishops.
Alien/Species Crossover: Return to LV-426: The story follows the RPG's lead in making the Xenomorphs extremely deadly threats, not only incredibly lethal but incredibly difficult to kill. When Pike and Lise go to chase down the four surviving escapees, it's believed the odds are ridiculously in favor of the Xenomorphs, when in most other Aliens media two people with fully loaded pulse rifles against four Aliens would be no problem. It takes twenty rounds to put down the first Runner, and most of their ammo to take down the third, as it uses darkness and mobility to evade most of their shots. Lise manages to kill one Runner hand to hand and injure the Drone, which Pike finishes off. The foundational premise is that, with nearly every encounter with Xenomorphs ending with the location in question consumed by nuclear fire, Weyland-Yutani needs to find more effective means of combating them to spare expensive equipment and installations. Oh, and lives, too.
In this story, Luz Noceda is the new bearer of All For One in this universe, giving her a level of inherent power that she never had canonically being a more direct threat in combat, thanks to all the Quirks she stole.
Unlike his canon counterpart, this version of All Might was able to put down All For One in their fight where he was just severely injured in the manga.
Eda has been working on controlling the Owl Beast rather than supressing it, since 24 years before the story began. So far it has gained her a Healing Factor and can temporarily control the One-Winged Angel form for a limited time without losing her mind.
In the show, King isn't much of a fighter due to his small size and young age. Here in this story, due to being in his mid-20s, he much bigger and more powerful, having access to to Titan Magic that he had yet to develop throughout the show. He's also strong enough that he's regularly tasked with physically restraining Eda when she loses control of her Owl Beast curse.
In the show, Gus's dad, Perry Porter, is just a news reporter. Here he's a Rebel Leader against Belos that managed to build and design an entire Underground City right underneath Bonesborough, which its roughly the same size, without The Emperor or his coven noticing for 14 years.
In canon, Masha was a regular human who was being sent to Camp Reality Check for some unspecified eccentricities. Here, they’re a student at Avengers Academy, having gained Chrome Champion powers as a toddler when their mother recklessly experimented with irradiated Orichalcum to "see what happens" (albeit under significant pressure from their government employers, and she's apparently still beating herself up about it).
Amity starts learning human magic here in addition to her canon Abominations and fire spell, and her tutelage from Doctor Strange allows her to destroy Grom all by herself.
Grometheus is much more dangerous here. One student that faced it previously has been in a coma since, and one of Boscha's mothers faced it and hasn't felt warm since, always wearing a sweater at least until Amity destroys it, ending its curses.
In Konosuba: The Adventures of Spider-Ham: Thanks to having the powers of Spider-Ham, Kazuma actually lasts longer in fights, even able to survive several of his canon deaths.
In Naruto Mystic Adventures: More than a year prior to the start of the original Naruto, Naruto was studying under Doctor Strange. By the time the series began, Naruto became a skilled shinobi and a sorcerer.
Arctic Rim does this to Anna and Elsa, the former becoming a hilarious badass and Elsa becoming a bona fide leader. The Precursors are also a lot more proactive here than in Pacific Rim, with one in particular (the story's Big Bad) who borders on Magnificent Bastard.
In Avenger Knight, while Batman's rogues have never exactly been pathetic, most of them have been relatively small-scale compared to some of the threats faced in the DC Universe. When thinking about Gotham's criminals, SHIELD agents such as Nick Fury, Clint Barton, and Natasha Romanoff all make it clear that they dread what those villains could do if they weren't fixated on Batman, observing that the Riddler is basically a one-man intelligence agency, the Penguin has sold more weapons than all of Stark Industries, and the Joker is The Dreaded as always.
Jaune Arc, thanks to getting trained by Ragna, becomes a much better fighter much faster than he did in canon. For example, his first fight with Cardin, which canonically was a Curb-Stomp Battle in Cardin's favor, has him more evenly match his opponent before managing to knock Cardin out of the arena and secure a win.
Since Penny is a Murakumo unit, her blades naturally float and lack the Achilles' Heel they had in canon.
Blood That Flows: Yuuno, a Non-Action Guy in canon, becomes 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.
Believe in the Weird and Wild: Due to being raised by a royal family of magic that's trained him since he was five, Steven is capable of beating up monsters and has great control of his shield, bubble, and floating abilities at age nine, while canon Steven only discovered his powers at age twelve and floundered with them for quite a while before learning how to really use them.
Not that Lucario wasn't a good fighter in the Pokémon world, but upon his resurrection on Ben's world, Lucario learns a number of other moves alongside his original Aura Sphere and Detect. As of now, the list includes Dark Pulse, Double Team, Life Dew, Extreme Speed, and Metal Sound.
Rook Shar is a downplayed example: she wasn't incapable of fighting in the canon series, but in Chapter 6, she is able to hold her own against Kundo alongside her brother, and she also uses a Revonnah-style scythe alongside her hand-to-hand combat.
Boldores And Boomsticks: Lillie and Casey receive unlocked Auras and Huntress training from Team RWBY, who are equals in combat to moderately-trained Pokémon. In the anime, they were just Trainers.
Bread Flubs: The Hated 7, SwaySway from Breadwinners, Sanjay from Sanjay & Craig, Pig from Pig Goat Banana Cricket, Pickle from Pickle & Peanut, Gus from Rocket Monkeys, Fraz Flub from The Brothers Flub, and Fanboy from Fanboy and Chum Chum all have special powers and eventually they have the ability to use a Care-Bear Stare.
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 than he didn't in canon. 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, Bagan is a straight-up Physical God here.
Kid goes from a moderately powerful captain whose high bounty is owed more to brutality than threat who uses his Devil Fruit primarily to hit people to someone who utilizes the full extent of his Magnetism Manipulation to terrifying effect, courtesy of a devastating loss to Grigori Vinci.
Tashigi takes a few levels after her fight with Bosque Herman inspires her to push herself even further than before.
In canon One Piece, Vice Admirals usually serve as Jobber types to show off how strong a character is by losing horribly to them. In this fic, Vice-Admiral class opponents are combat monsters capable of taking on entire crews single-handedly without taking a scratch.
Cards of Remnant: In RWBY canon, Jaqces Schnee is simply a Corrupt Corporate Executive with no combat abilities at all. In this Yu-Gi-Oh! crossover, he's an extremely powerful Xyz duelist, with Galaxy-Eyes Photon Dragon as his ace monster. Unfortunately, this also allows him to go from being simply emotionally abusive to Weiss to straight-up physically abusive, and personally gives Weiss her canon scar in a duel.
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 Noodle Incident, the physique of a man in his prime. And as he demonstrates on HYDRA troops, his abilities go far beyond simple screaming and he most definitely knows how to use them.
The Winter Soldier progresses from street-level nightmare to the terror of the entire Western World, an immortal wraith-like figure and One-Man Army who induces pants-crapping levels of terror from just about anyone who hears of the possibility that he might be around. While part of this is his legend taking on a life of its own, he backs up the hype: he's one shotteda former Captain Britain, for instance. In one of his rare on-screen appearances, he's killed 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 Steve, Natasha and Clint and having them dead to rights.
Harry packs increasingly more power than in canon; initially magical, later psychic (on a scale that he's the only person other than Maddie Pryor who's even in the same weight class as Jean Grey) and physical as well, meaning that he goes through the gears from One-Man Army to Person of Mass Destruction(which is good, because it's that or die). He's also growing into a fully-fledged Guile Hero who goes from random Indy Ploys that function as tactical Confusion Fu (and don't always work) to full-on Xanatos Speed Chess flavoured with a Batman Gambit or two in the sequel. He's also a lot more confident and assertive, and has Wanda's blessing at his back, meaning he's even more of a Magnetic Hero than ever. By Book III, even limited to 'just' telekinesis and his Flaming Sword (currently functioning as a lightsabre to boost his Obi-Wan impersonation - and yes, It Makes Sense in Context), he casually demolishes a Brood Queen and her warriors, and destroys a Kree Sentry, a war-robot that's previously been an Avengers-level threat all by itself. He does both without breaking a sweat, and the latter while musing on his Blood Knight tendencies.
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, he steals some of Harry's Psychic Powers, 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 Combat Pragmatist with no inclination towards the kind of Bond Villain Stupidity he showed in the books.
In the MCU, Thor is a Flying Brick with Shock and Awe 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.
Though it's downplayed, Sirius Black, already no slouch with magic in his canon form, is a master duelist, having earned the Red Baron of "The Marauder." He doesn't like it much.
Canon Wanda Maximoff suffered from constant Power Creep, Power Seep. How powerful is she here? Well, she's the former apprentice of StephenStrange, and, in an Offscreen Moment of Awesome, pulled a Colony Drop on Nicodemus Archleone. In Unfinished Business, she goes one on one with Nimue, who's channelling half the magic of the Earth and holding off entire pantheons with a metaphorical fingertip. The only others who manage to do that are Merlin (most powerful sorcerer ever), Doctor Strange (most skilled sorcerer ever with 500 millennia of experience), and Carol (who has the other half of the power). The former holds her to stalemate for a while and tries to talk her down, the second seriously hurts her but doesn't get away unscathed, and the third mostly has to resort to physical brutality and draining her power. Wanda duels her and mops the floor with her, to the point where she's forced to resort to a major diversion.
Children of an Elder God: 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...
All of the Black Knights get this by not only having the Autobots as allies, but also receiving upgrades to their Knightmares, allowing them to slowly catch up, and likely exceed in time, Britannia's fighting ability.
In R2, the Guren SEITEN, the Lancelot Albion, and the Shinkiro, which were already some of the most powerful and badass Knightmares in canon, become even more powerful as they are made from Cybertronian Protoforms, and the Lancelot Albion and Guren SEITEN can now transform.
Following the Time Skip to R2, Lelouch becomes a better pilot and learns hand-to-hand combat thanks to intense training from Ironhide, Tohdoh, and Sayoko. In addition, his Zero costume is now a suit of armor incorporating Cybertronian technology, with features including hover skates and energy blades.
If Megatron's canon abilities weren't terrifying enough, he also gets a Dark Geass, which he receives without needing to make a contract with V.V. or C.C. With it, he can expose people to their greatest fears, and can kill them with it if he wants to.
Optimus receives his own Geass as well from making a contract with C.C., the Prime Geass of Absolute Conviction. With it, he can reignite the hope within people's hearts, and can fight off Megatron's Dark Geass.
Jeremiah Gottwald was already badass in canon as a cyborg, but he's even more badass here as Shockwave is the one to turn him into a cyborg with Cybertronian implants.
Though she doesn't see any action throughout the story, Nunnally becomes a Badass Pacifist in R2 after regaining her sight and ability to walk, refusing to show fear when facing her enemies.
Coreline: This is the essential fate of anybody who enters the post-multiversalReality BleedWorld of Badass of the setting. They all 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 Badass Bystander who's had enough).
In the stories written by Crossoverpairinglover on Fanfiction.net, virtually every character gets upgraded to the point they are badasses. Genuine Lockharts, super saiyan-like Sakuras, Apollos who create black holes, etc.
In canon, Finn was barely a match for a Force-sensitive, while here he is The Dreaded by the powerful and cruel demons. He eventually gets power from the Daughter herself, and can match Ganondorf.
Ganondorf also gets this treatment, having sold his soul and redeeming traits for a lot more power. Now he can control the hate and Dark of others. Plus, he gains an even stronger form.
The other characters are buffed less, but still. Rey beats demons while pregnant, Kylo can summon comets and Hellfire, Link brings down Star Destroyers, Rose Tico manages to nearly turn the tables in a fight, Zant has now a second form...
Rex Raptor gets to show just how competent of a duelist he is while dueling Makoto. Even though Makoto wins, it was not easy.
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 Marik.
Fred is a former Army Ranger, Velma has doctorates in several fields, Daphne honed her martial art skills, Shaggy is an (unpolished) amateur sorcerer and Scooby Doo is his familiar.
The Hex Girls, instead of just a Goth-themed girl band who encountered the supernatural, are actual witches with different areas of magical expertise, serving Elvira, Mistress of the Dark.
Equestrylvania: In Castlevania: Aria of Sorrow, the Chronomage was just a quickly defeated obstacle. In this story, he's an active villain, able to fight Aeon one-on-one repeatedly, and wins several times.
One of the most prominent examples is Wendy, who receives training from Sparda’s former apprentice Modeus following the Edolas Arc. As a result, she hones her skills to a far greater degree much earlier than in canon. By the time the Tenrou Island Arc comes around, she’s managed to master Shattering Light: Sky Drill, a move she didn’t learn until the Grand Magic Games arc. The most prominent example of her training comes from her match with Sherria during the Grand Magic Games. Whereas they both drew in canon, Wendy manages to win here by displaying more tactical acumen and even identifying Sherria’s shortcomings and weaknesses.
Due to being an Ascended Extra in this story, Lisanna gets more chances to show off different animals of her Take-Over Magic that weren’t displayed in canon. In addition, she receives a Dragon Soul thanks to a blood-based dragon ritual from Natsu.
Trish is just as formidable in canon, but here she eventually gains her own Devil Trigger, boosting her power level to match many of Fairy Tail’s heavy hitters.
Lady, already a Badass Normal in canon, becomes a Steel Devil Slayer after having a lacrima placed inside her by Arkham.
Due to the events leading to his death in canon being avoided, Modeus gets more chances to show the skills that come with being a student of Sparda’s, and his own teachings play a big part in Wendy improving heavily as a fighter herself.
Nero becomes more of a badass, as not only does his Devil Bringer display Energy Absorption powers (something that wasn’t shown in canon), but he also gets a bigger arsenal due to acquiring the Devil Arms from Devil May Cry 4.
Following the Time Skip, Lucy undergoes training to become a Devil Hunter herself. By the time the Grand Magic Games arc comes around, her match with Flare is a Curb-Stomp Battle where she dominates her opponent in hand-to-hand combat, only losing because of Raven Tail’s interference. On top of that, she can also cast Urano Metria at will and has access to another trump card.
Kyrie, who didn’t display any type of powers in canon, is revealed to have a Lost Magic called the Arc of Seraph, one of the first magics to be wielded by mankind.
During the Grand Magic Games Arc, Elfman reveals two new Beast Souls that he lacked in canon; Hawk-Man for flight and enhanced speed, and Werebear for even greater strength.
Downplayed with Juvia, but here she gets to display more competence when in battle, frequently displaying great perceptive skills and even willing to tone down her feelings for Gray when things get serious, making it clear why she was S-Class in Phantom Lord.
After being expelled from Fairy Tail, Laxus trained to better harness his Dragon Slayer Magic, to the point that he can now enter a proper Dragon Force when in battle.
Following her loss to Mirajane in a case of Worf Had the Flu, Jenny from Blue Pegasus gets to truly show off her skills during the fourth day of the Grand Magic Games. In the Naval Battle, she manages to hold her own briefly against Risley and Sherria, and during the 3-on-3 battle against Quatro Puppy, she defeats Rocker and Yeager by herself while Ichiya defeats Bacchus. On top of that, she’s noted to be Blue Pegasus’s ace, holding the rank of S-Class.
Mermaid Heel in general gets this treatment. While they were no pushovers in canon, the only prominent members they had were Kagura and Millanna. Here, they are the second strongest guild in Fiore behind Sabertooth, and their guildmaster Kurenai is the Number One Wizard Saint. In addition, they have two S-Class mages in Lucia and Sapphire, and some of their members have new abilities. As a result, they do far better in the Grand Magic Games, and by the end of the fourth day, they’re right behind Fairy Tail in second place, and ahead of Sabertooth by ten points.
Most notably among Mermaid Heel, Kagura’s sword the Archenemy is turned from a normal magic sword into a Devil Arm capable of absorbing attacks for extra power.
Risley Law can use her Gravity Magic to absorb the impact of her opponent’s attacks into her body to power herself up, something she didn’t display in canon.
In canon Rogue was usually seen with a katana, though he never seemed to use it. Here, he takes inspiration from Vergil and incorporates said sword into his fighting style with his Dragon Slayer Magic, creating a form called “Shadow Dragon: Sword Style. In addition, Mira and Lady sense demonic power mixed in with his magic.
Kain Hikaru was mostly just a joke villain in canon, whose Made of Iron status was Played for Laughs, with his own voodoo magic used against him. While he is still mostly comic relief, he also benefits from Adaptational Intelligence, using his magic on himself to give his body the properties of diamond, lava, smoke, steel, and even light. As a result, he forces Lucy and Trish to flee and it takes Dante and Cana to get an advantage when fighting him.
The various members of the Neo Oracion Seis are more dangerous than they were in canon. Midnight, Racer, and Erigor undergo the Ascension Ceremony allowing them access to demonic forms, Klodoa’s form of Gilver is more threatening than Jackpot, Gloria is a greater threat than Angel/Sorano, and Cobra gains access to Dragon Force.
In canon, Obra from Raven Tail wasn’t much to look at, with his only threatening status being his ability to drain others of magic. Here, he can absorb magic and demonic energy to further empower himself, can withstand attacks from Laxus and Sapphire, and was recruited by Ivan specifically to fight Dante.
Fairy Without Wings does this simply because of its setting to the entire case of Code Geass. In addition, Jenny is a legitimately powerful mage, Princess Hisui has shown she's not PrincessPeach, and the Rune Knights are now capable of fighting some of Fairy Tail's best with some of their best.
Fate Azure Destiny: Though Ritsuka Fujimaru still thinks of himself as an amateur, he is much more competent at using spells and can use Reinforcement to boost his strength enough to battle the Shipgirls and Sirens. It was a plot point in canon that Ritsuka sucks at spells and cannot use Reinforcement on himself.
Firebird: Taylor gains Jean Grey's powers, which eventually entails to her gaining the powers of the Phoenix Force. This leads to her easily defeating Simurgh and resurrecting the entire population that was killed in their ensuing battle with little more than words.
In Flashpoint 2: Advent Solaris, many of the Sonic characters now unshackled by the limitations of being in a video game are shown to be much more powerful than in their original source material - with many of them comparing well to the DC characters they are presented alongside.
In Freedom's Ring, the 104th Trainee Corps receives this treatment big time. In canon, they were just barely out of training rookies who were easily decimated when the titans invaded Trost and only able to turn the tables by Eren transforming into titan and the Survey Corps coming at the very end. Here, they were supplied with modern weapons in the form of Barrett .50 anti-materiel rifles and M2 Browning heavy machine guns, not to mention received training from none other than the United States Army Rangers on complimenting it with their Three Dimensional Maneuver Gears. As a result, they became a deadly titan-hunting squad who were able to repel the titan incursion on the now-liberated Shiganshina District without incurring any casualties on their part. In fact, the only hiccup to their newfound success was Eren's transformation itself on part of a deliberate sabotage courtesy of Bertholdt.
The Games We Play (The Gamer/RWBY) turns Jaune from Butt-Monkey to legitimate badass via the mechanics of The Gamer. In canon, he's far, far behind any of the other main cast. Here, he's able to, among others, beat Weiss, turn a Delaying Action against Penny into a win, fight Pyrrha to a draw, bluff his way out of fighting Cinder Fall, and outfight Raven. And he hasn't even gotten into Beacon yet!
In the original canon, Ben's fighting style was focused almost entirely around his aliens. Here, he incorporates his soccer skills into his combat style as a human. When he fights with Cardin as a human in chapter 39, he destroys the jerk. He also gets his Aura unlocked by Maria in chapter 44, though it's apparently on Kylie's level compared to Ruby's due to his Osmosian genetics from his grandmother.
Yang managed to go toe to toe with both Fourarms and Cannonbolt, aliens who have taken down giant robots and survived re-entry into Earth...and win.
The authors give Roman a semblance, akin to Loki- he uses his "silver tongue" to persuade others to do his bidding. It apparently has some limitations though, as it doesn't work on Fistrick, for starters.
Albedo is much more equipped to deal with Ben; his forms are "edited" in a sense, with his Humungousaur having his canonical Ultimate's "missile arm". His ultimates are also...much, much more different. Albedo's Ultimates also have a buff in this universe- Ultimate Grey Matter can create life from nothing, Ultimate Arctiguana can freeze objects in place similar to using Zero Point Energy and Ultimate Wildmutt has three heads, each with their own respective elements.
Glowworm: Taylor gains the powers of Shazam! from The Wizard, making her the physically strongest hero on Earth Bet.
The Polygon Man is heavily given this treatment in God of War: Chains of the Heart. In Playstation All Stars Battle Royale, despite being a Reality Warper, he could still be defeated by any individual character. In Kratos' retellings of those events, it required everyone in order to truly defeat him, and the Spartan still regards the Polygon Man with great fear.
Tachibana Tetsu, the Handicapped Badass of the group, has Sky Flames, which have the Harmony Factor. While its exact properties are not disclosed, he can float, and can go on par with Majima.
His sister Makimura Makoto has Sun Flames, which grant her Healing Hands, a Healing Factor, and the ability to activate other people's Flames.
Kiryu Kazuma has Lightning Flames. With those he can No-Sell most attacks including rifle bullets, and he can also create Lightning barriers.
Other Like A Dragon characters who now have Flames (but don't show their abilities on-screen) are Oda Jun, Sera Masaru, Kazama, and Saejima Taiga.
The Good, the Bad, and the Demon has April O'Neil and her best friend, Hitomi Tono. In the former's case, using more of her psychic abilities ever since she found she's half-human, half-Kraang, while the latter has learned to fight with April's help.
Daolon Wong is much more powerful than in canon, having access to magic created by the Demon Sorcerers.
Jade ends up counting as this too, as her new Ben-Shui and Shapeshifter powers make her strong enough to fight Cedric or Wong on equal footing, making her more or less as strong or even stronger than an individual Guardian.
This story's version of the Dark Hand takes the cake, however. What in canon was nothing but Valmont's personal organization, already fallen from grace by the start of the third season, here becomes a global criminal empire, spawning over five continents, each under the influence of one of the organization's five branches, with the likes of Bartholomew Chang and Vanessa Barone as their leaders. They are shown to be far more competent and resourceful than in canon, and after the Wham Episode that was Chapter 19, it's revealed that the Dark Hand is nothing but the tip of the iceberg of a kind of a Government Conspiracy, pulling a False Flag Operation with the likes of Section 13 so Earth gets aware of and weaponizes magic. One of their leaders is even Captain Black's direct superior. A far cry from what canon was, indeed.
As is common for JCA fics that utilize them, the Samurai Khan are treated as Elite Mooks, rather than the Fake Ultimate Mooks they were in canon. They're physically stronger than other tribes, are slightly resistant to magic, and have enough self-awareness to adapt their combat strategies.
The Heroes of Time does this to the Hanna-Barbera universe. Most of the characters in the shared world are rather peaceful people and never mean harm. But when The Heartless invade and start swallowing worlds, it's time to take up Keyblades and fight.
Incarnation of Legends: Rakia gets this big time as with Romulus helping them, the army becomes a lot tougher and more successful, going from a complete joke for Orario to defeat under Ares' control to something that threatens to conquer the Royal Alf Forest.
Infinity Train: Blossoming Trail:Chloe Cerise in canon had little to no experience in Pokémon or battling — as the story takes place before Chapter 29 — and her only contribution was just using Yamper's Spark on an already weakened Gengar. When she gets onto the Infinity Train, she slowly becomes a fighter with the use of her donut holer, obtaining power-ups and artifacts to even the battle to the point that she's the one giving commands to everyone else in The Fog Car against two monsters that wouldn't look out of place in Silent Hill.
JoJo's Alien Adventure: Ben is undoubtedly a powerful fighter, thanks to the Ultimatrix, but his power is further improved by the simple fact that here, Ben becomes a Stand User. His Stand, Emerald Ace, works incredibly well with the Ultimatrix, as it too can use any alien Ben can use and use the Ultimatrix's Evolutionary Function. Finally, Ben and Emerald Ace, if both are in alien form, can perform a Fusion Dance to morph into combined forms. Additionally, Joseph and Avdol, learning of DIO's interest in the Ultimatrix from Devo the Cursed, plan on training Ben in Hamon as a protective measure.
Darth Nihilus. In the games, Nihilus was overly reliant on his Force Drain to the point of it being a Crippling Overspecialization, and turns out to be a complete pushover without it. This version has a much wider skillset, being a Master Swordsman knowledgable in several lightsaber forms and an Evil Sorceror who wields ancient Sith magic. He's also more action-oriented, being depicted as a One-Man Army who prefers fighting up close and personal rather than an Orcus on His Throne like in the games.
This also applies to Darth Nihilus' backstory. In Star Wars Legends, he was a textbook example of From Nobody to Nightmare. Here, he's a former Jedi warrior who Revan personally trained, and was even capable of going toe-to-toe with a pre-Sith Malak in a lightsaber duel.
During the Breach, when the Grimm attacked Vale in canon, they were easily beaten back by Teams RWBY and JNPR before backup even arrived, at which point the Grimm were absolutely massacred. Here, the battle is nowhere near as one-sided with the heroes being driven to the point of exhaustion, nearly killed on several occasions, and even briefly overwhelmed by the Grimm's Zerg Rush. In fact, Jaune's 11th-Hour Superpower is the only reason that any of the main cast even survive. Additionally, this fic has more powerful Grimm subspecies present at the Breach such as Griffons, Beringels, and a unique King Beringal.
Amber, the previous Fall Maiden, also gets hit with this. In canon, she was described as being an "inexperienced" Maiden, explaining away how Cinder was able to defeat her and steal half her powers. Here, Amber is established to have been a professional Huntress who graduated from Beacon and has already achieved full mastery over her powers.
Justice League of Equestria: Deathstroke has always been a skilled fighter in The DCU, but here he manages to get the drop on Rainbow Dash (this universe's equivalent to Superman) in their first encounter and then manages to almost defeat her again during their fight in Cloudsdale.
Kabbalah: The Passive Conqueror: Though this fic is set during the Cosmos in the Lostbelt arc, Mashu Kyrielight has not lost her powers and doesn't need the Ortenaus device to fight. The author admitted to hating that little detail and removing it.
Canonically the only time she surpasses Lily in ranks is as Kazuya's chosen Angel. Here she achieves an original rank called 'Omega Commander' - basically a seven-star general.
Her natural aura includes a purifier so strong her body produces a Phazon variant with selective targeting that has no negative effects whatsoever on her body.
And speaking of Metroid-origin powers, her Missile system upgrades into far greater lethality and explosiveness through an unusual side effect of a far more enhanced vaccine "Metroid" that only befell her. It isn't until a visit to planet ZDR that she finally regains the original system - as well as a number of 'Perfection Upgrades' (including one to said system) via several X Parasites blindsiding her (the third one, with the 'Perfection Upgrade' to her Light Beam, implying that these X were inadvertently unleashed during her World of Light mission, which is not helped when said mission's version of Galeem as an AI embeds into her Power Suit along with a matching equivalent of said mission's version of Dharkon via the following X). Said Suit itself is from a line of original models Khaos devised, this one armed with both an aura that can kill non-immune Metroids on contact and a Supernova variant of the Nova Beam alongside the line's one constant in the form of flight-enabling wings.
Some of these 'Perfection Upgrades' are Fusion-variants, combining traits of two or more regular 'Perfection Upgrades' to create far more hyper-lethal superweapons. Included are a Plasma Beam/Imperialist fusion dubbed "Eagle of Flames", a Spacetime Beam (a known glitch weapon from Super Metroid)/Judicator fusion dubbed "CosmicGlitchTornado", a Nova Beam/Imperialist fusion dubbed "NuclearReichbuster", and a Charge Combo fusing the Nova Beam, Plasma Beam, and Annihilator Beam with the name "Absalon Howitzer Eclipse". That last one is how she learned the Galeem and Dharkon AIs were from her World of Light mission, as when commenting on its use they quipped that they were not on the receiving end of it for once.
Ben still uses the Omnitrix like in canon, but here, he is also able to tap into his Anodite side as a flight or fight response.
In canon, Flamberge and Zan Partizanne were solely capable of manipulating fire and electricity, respectively. Here, however, they are capable of manipulating other elements: Flamberge can control earth while Zan Partizanne has power over wind.
Sword and Blade Knight were skilled fighters in their own right and trained by Meta Knight, but here, they can empower their swords with elements like in Kirby Star Allies to form them into elemental swords.
Of course, they don't really compare to Julie, who takes a massive level in badass here. In canon, she was an ordinary human but owned Ship, allowing her to form Powered Armor in combat. Here, however, she is revealed to have a connection to the Jambastion religion as their high priestess and thus has the ability to manipulate all elementsused by the Three Mage Sisters: water, ice, fire, earth, electricity, and wind.
Last Child of Krypton does this to plenty of characters, but first and foremost is Shinji Ikari, who turns out to be half-Kryptonian in the story. Later examples also include Asuka, Toji, Rei, Kaji, and Naoko Akagi.
The Last Daughter: While Taylor Hebert was already badass in Worm, here she ups her badassery by several orders of magnitude, where she is actually Kryptonian. Virtually every fight she's in is a Curb-Stomp Battle in her favor, and she actually manages to kill Behemoth.
Legacy (Sekiro/Kimetsu no Yaiba): Tamayo is the daughter of Emma the Doctor in this story. As a result, she's trained in Emma's brand of Ashina-style swordsmanship. When combined with her demonic strength and agility, she's a dangerous opponent on par with Wolf.
Lighting Candles: In canon, Tadashi was a Nice Guy and brilliant robotics student whose most heroic moment was coming in on his moped to save his little brother. In this fic, after he died, the Man in the Moon chose him to be a new Guardian, and turned him into a fire kitsune, giving him the powers of pyrokinesis, shapeshifting, flight, dreamwalking, etc.
''Lord of the Castle: Dracula's castle is this compared to its depiction in the series, as it bears more of its Eldritch Location aspects from the games, constantly leaking out evil that can only be countered by the presence of salt in the ocean or else cause death to anything living nearby, and capable of changing its interior on a whim and teleporting to other planets. The castle itself is also sentient, and capable of separating minds and bodies, and has its own urges, such as revenge when its master gets threatened.
Loud Ed Drama Heather is still the main antagonist of the story, but she is more socially savvy than she was in canon, where she let herself be openly hated at all times.
In her first battle against some thieves, she reveals that she took a page out of Zero's book by copying his Charged Slash between the second and third games.
Her blueprints were altered when she was first built, resulting in a collection of hardware that she should've immediately had access to being heavily encrypted and inaccessible. Said hardware, which includes such things as a Double Jump and the ZX series' Overdrive function, is slowly unlocked as she fights opponents who incorporate similar abilities.
The aftermath of her fight against Trifecta reveals that she's inherited the Mega Man line's Variable Weapons System due to the DNA she inherited from X, albeit a variant revolving around her ice manipulation and Frost Javelin. This helps her survive a duel with a dragon that otherwise would've killed her.
Granted, the Mask was already Badass in canon, but here, he was created by Loki to kill Thor.
While Max Caulfield in Life Is Strange was a fragile waif who happened to develop the Time Rewind Mechanic without explanation, in The Matrix Rewinds she's the current iteration of The One, with all the martial arts mastery and unique abilities within the Matrix that her predecessor Neo possessed in addition to her time powers.
Mortal Kombat vs. The Owl House: Downplayed with Shang Tsung while he is about as powerful in terms of magic and skills as he is in canon, we do get to see him defeat more opponents than in canon including some he has canonically lost to like Liu Kang and Shao Kahn though with In-Universe reasons for both.
My Huntsman Academia: All of the My Hero Academia characters that have been transplanted into the story have all the benefits of possessing an Aura, including a constant forcefield, varying levels of Super-Strength, and a Healing Factor. Izuku makes extensive use of the last one to use his finger-breaking Smashes more liberally without risking long-term harm to himself. Aizawa's Semblance also doesn't have the restriction of being unable to cancel out constantly active Semblances the way his canon counterpart does with Quirks. This comes in handy when he and Toshinori are facing down the Noumu at Mountain Glenn, as Aizawa is able to temporarily cancel out the Noumu's regeneration so Toshinori can soften him up.
My Ideal Academia: In canon, Aoyama only helps Uraraka restrain Thirteen's other hand, while Uraraka does all the hard work handcuffing Thirteen in their examination. In this fic, Aoyama fights Thirteen alone with the skill he gained from Shirou's training. He does an excellent job at it. Aoyama manages to catch Thirteen by surprise with his laser and disorient her, buying enough time for Uraraka to escape and earning Thirteen's praise. It's implied he would've shot another laser at the disoriented Thirteen, potentially winning the examination by knockout, if Uraraka hadn't escaped a few moments later.
With the Ladybug Miraculous, Momo's "Creation" quirk has a significant boost since the Ladybug Miraculous grants The Power of Creation.
With the Cat Miraculous, Tomura's "Decay" quirk has a significant boost since the Cat Miraculous grants The Power of Destruction.
The Myth of Link & Zelda: Breath of the Wild gives a major boost to numerous characters, some of whom were meek and others who were already badass. Link and Zelda are even more powerful since they control massive animal spirits that grant them powers equivalent to gods. The originally feeble and elderly Impa shows that she's no slouch in a fight, and Paya starts out as the meek shy girl she's famous for being before becoming an incredibly powerful magician in her own right. Even Calamity Ganon is more badass, shown fighting with much greater aggression than in the game, even nearly killing Link at one point.
In the comics, the Ultra-Humanite is known for his vast intellect and superhumanly strong gorilla body, but mainly relied on his various gadgets to take on the Justice Society of America. In this story, he has a powerful Quirk called "Over Man", which reduces the physical capabilities of all humans within 100 m of him by 75%. With this, he's able to take on Izuku and All Might simultaneously!
In the manga, Tokoyami's "Dark Shadow" is a fairly powerful Quirk. In this story, on the other hand, it's a genie from the 5th Dimension named Tskymi, who can grant wishes to Tokoyomi without being limited by anything so quaint as the laws of physics.
In one Elseworlds story titled "Be Humble", little Eri, a Broken Bird in the original My Hero Academia, is imbued with the powers of the Greek goddesses by the wizard Shazam, making her the super-powerful Flying BrickShazam!.
In Street Fighter/Evangelion crossover Neon Genesis Evangelion Senshi No Michi, Shinji and Asuka are raised by Gouken and trained in the Ansatsuken martial art. Rei learns Dan Hibiki's ridiculous style and somehow she makes it work. And Hikari and her sisters, who are ordinary high-school students in canon, are ninjas.
A New Problem: Thaz, the landlady from "Neon Knome" (the pilot of The Problem Solverz) Thaz seems to be a normal middle-aged woman. But in this story, she secretly has superpowers and can transform into a superpowered hero.
Several of the main female characters of Kuroinu are given this treatment as opposed to canon, where they are forced to become Sex Slaves.
Olga, Chloe, Maia, Alicia, and Claudia have at least one fight scene on the battlefield, where they prove to be either competent combatants or commanders leading the charge. Olga, in particular, goes through this trope a second time in the remastered version of the fanfic, having access to a lot moremagicalabilities for combat than plain Playing with Fire, allowing her to last a bit longer against the Good Hunter.
No Gods, Only Guns: Ambassador Donnel Udina becomes a full-on Guile Hero, humiliating the batarian ambassador in front of the Council, and also possessing an eyepatch and cybernetic hand. Doctor Michel, usually a Damsel in Distress, 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.
Omni Evolution: Ben's powers have been amped. Not only can he transform with a mere thought, but he doesn't have any time limits like he does in canon. In addition, he's only nine years old yet all this power lets him casually steamroll the X-Men without much trouble.
Oni Ga Shiku Series: In canon, Naomasa Tsukauchi is firmly a Non-Action Guy, and it's unclear if he has a quirk or not (at least he's never seen using it). In this fic, not only does he have a Living Lie Detector quirk, but he also helps Izuku beat the crap out of the entire Yamikumo Clan - as in, a yakuza family.
Paper Mario X 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.
Persona EG: Flash Sentry, as the main character, is a Wild Card, is very good at playing Guitar, seems to be a Chick Magnet, and has gotten good at swinging a battle axe around. Not bad for a fairly minor character from the Equestria Girls movies.
Aunt Jemima can duel wield maple syrup bottles and even make armor made out of maple syrup, which she uses to shield Barney from Heinel's deadly tater tots.
Katherine uses a sword, but in the original Voltes V anime she had no weapon.
Reapers Among Fairies: Karin and Yuzu Kurosaki are a Shinigami and Quincy respectively, while in canon, Karin only had a little power and Yuzu never awakened any. The Kurosaki family had 15 years to train and are all fighting machines, plus Ichigo can use Kido spells.
In RWBY, Jaune didn't display any combat proficiency until after his training with Pyrrha. Here, he manages to take on and kill several Possessed during the assault on Vale before he unlocked his Aura.
Since Marcus Black was killed off-screen as part of Mercury's origin story, it made his status as a notorious assassin come across as an Informed Attribute. In this story, he not only survives his son's attempt to kill him, but he's the leader of the Demon cults on Remnant and is capable of fighting the Doom Slayer, Qrow, Hazel, and Ozpin at the same time.
In DOOM Eternal, Deag Nilox was quickly killed by the Slayer at the beginning of the game and only stood still and cowered the moment he became vulnerable, while here he uses magic to defend himself and repel both Ruby and the Slayer.
The Marauder plays with this trope. In DOOM Eternal, while one of the toughest enemies in the game, he could still be defeated by the Doom Slayer on his own. Here, his first appearance is one of the few times the Slayer is backed into a corner and beaten to the point where he can barely move, and his second appearance required that the Slayer work together with teams RWBY and SSSN along with the White Fang to kill him. However, by the time they encountered in Eternal, the Slayer was much stronger thanks to all the enhancements and weapons he gained over the course of the game, while his encounters with the Marauder here are before he gained those enhancements and his arsenal at the time had fewer tools, so it's less of the Marauder being genuinely stronger than canon and more of a standard Marauder fighting against a lesser Doom Slayer.
Remnant's Bizarre Adventure: In Steel Ball Run, Eleven Men was an unimpressive enemy who only managed to pose a threat to Johnny and Gyro because the two of them were racing against the clock to avoid the effects of Sugar Mountain Tree Spring. In this fic, he's a cunning and pragmatic Professional Killer who manages to thoroughly defeat Yang Xiao Long even after Yang learns to fight like a Stand user.
Roller Brawl: The Mega Cyborg: Bubble Man is given this treatment. Retaining some of his abilities from Mega Man 2: The Power Fighters such as a bubble shield and trapping bubbles, he's a much more serious threat than he was in the comic, and while he is the Starter Villain and thus still easy to destroy, he is far from the Butt-Monkey he was in the original comic, where he was destroyed by a weapon he wasn't weak to. The worst he has here is some grumbling about his unthreatening name, wondering why he didn't have a name like Scuba Man or Aqua Man.
Aizen has a Sword Beam attack, actually uses his Bankai, and his final battle with Ichigo is much more impressive.
Scoob and Shag: The majority of the characters go from their comical cartoon selves to an assemblage of soldiers, spies, and heroes — having unique superpowers helps — but some stand out in particular.
Scooby-Doo is canonically an intensely cowardly and rather incompetent comic-relief character. In the comic, he's a veteran of an interplanetary war, a former army commander, and a dangerous and stoic fighter.
In the original cartoon, Dee-Dee is a regular preteen girl who mostly gets herself and others in trouble when messing with her brother's machines. In the comic, she's a soldier willing to sacrifice her own life for the sake of a vital mission's success, and by Part 2 has become a competent fighter and infiltrator.
Garfield is canonically a fat, lazy lump who's only really dangerous to spiders and people who try to steal his lunch. Here, he's a trained spy sent to infiltrate the White House to hold the President captive.
The Secret Keeper: The reason why Bella Swan of The Twilight Saga was so passive and lacking in self-confidence in the novels is revealed; she's actually a muggle-born witch who has spent the last six years attending Hogwarts before Voldemort's return and the death of Dumbledore prompted her to return to the states, leaving her uncertain how to interact with non-magical people and significantly behind in what is expected of her coursework. Needless to say, once she's able to tell the Cullens about her magic, she swiftly impresses them with some fancy Transfiguration skills and a fully-formed lion patronus, among other tricks.
Shinobi of the High Seas: While Naruto Uzumaki has grown into a powerful badass in his own manga, this story turns him into a Showy Invincible Hero that manages to go through the Grand Line and ultimately fight Aokiji, one of the most powerful admirals in One Piece, to a standstill.
Canon Ruby mainly relied on Petal Burst and Crescent Rose in combat, and sucked at hand-to-hand, and was constantly underestimated. Here, one of Ajuka Beelzebub's prototype sets of Evil Pieces was used to make her King of a peerage of Angels, granting her such a boost in power and change in demeanor that Roman Torchwick immediately pegged her as dangerous, and she was able to defeat all of his Mooks without even drawing Crescent Rose.
Somewhat deconstructed with Yang. Becoming Ruby's Rook has made her so strong that her Semblance had to be sealed away so she wouldn't destroy everything around her, and she has to either pull her hair back or get it cut before a fight, to prevent her Hair-Trigger Temper from taking over.
Meanwhile, Jaune is a heavily downplayed example. Some Training from Hell from Blake had him with an unlocked Aura, and while he didn't get details, asking some Beacon washouts for information got him enough details that he packed some exploration tools and a topography map of the Emerald Forest for the entrance exam.
Six Paths of Rebellion makes a fair number of Code Geass characters anywhere from slightly to immensely more badass than canon. While Kallen gets a Geass, Rakshata, Sayoko, Euphemia, and Nunnally all gain the Rinnegan and become one of C.C.'s 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.
Luffy gets the Goro-Goro No Mi instead of the Gomu Gomu No Mi, which makes him far more effective in the Thriller Bark arc, allowing him to beat even Kuma.
Makino joins Luffy/Ranma on his journey and due to training with both Luffy and Garp, knows Armament Haki. Considering that in canon she is not a fighter, that makes her far more powerful.
Star Wars Episode I: The Familiar of Zero: While the canonical Foquet the Crumbling Dirt is skilled at making giant golems and not much else, here 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 Derflinger but has been studying under a Sith lord.
Star Wars vs Warhammer 40K: Prequel-era Palpatine in canon was a human Sith Lord in his sixties who, despite being a highly skilled lightsaber duelist with an impressive mastery over the Dark Side, was rivaled enough by Yoda that he was wary of the little green Jedi Master, and their duel in Revenge of the Sith saw them almost evenly matched with Yoda overpowering Palpatine in both a Blade Lock and a Force struggle. Here, Palpatine is portrayed as an over 1000-year-old Transhuman Abomination possessing god-like powers that would make Abeloth afraid. In the actual story itself, when he decides to personally intervene during the Axum arc after the Jedi prove too weak to defeat the Arc Villain, his power is so overwhelming that each of his attacks cause reality itself to violently distort, and Palpatine is even able to Mind Rape and Force-Choke a fully-realized Alpha-Plus psyker into near-submission. It goes without saying that Yoda stands precisely zero chance of defeating this version of Palpatine in a duel where Palpatine isn't holding back, something which is confirmed both by characters within the story and by the author himself.
Storms Overhead has Louise and Henrietta get an upgrade; the former packs new Void element spells that 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.
Finn in the Prologue, the Battle of Exegol, is even tougher than his canon counterpart. He gets inside the enemy capital ship and slaughters an Executioner who had a Beskar chestplate and a Force-using Sith Acolyte easily. He also had fought a Knight of Ren to a standstill. And he only gets stronger from there.
Leah Clearwater has defeated the Volturi, especially Jane, on her own. And she only becomes stronger from there.
The Knight of Ren who had fought Finn. In Star Wars, the Knights didn't do too much, but here this knight saved Kylo from a headshot.
Sir Arthur of Ghosts And Goblins can now use combinations of multiple weapons at once and his armor can take more than one hit.
Renesmee can use her gift to effectively lead a vampiric army.
Adrian Andrews can now use a whip and fight bad guys, including supernatural ones.
Alix has become much stronger than her Chronicles of the Cheysuli canon counterpart and is able to take on giant Yokai.
Charlotte Smoothie in her canon was a powerful Sweet Commander, but she didn't have any major fights at all. Here, she is a terrifying warrior who only didn't contribute in Wano because an outsider joined the fight to save the weaker Straw Hats from her. Smoothie proceeded to beat the outsider after a very long fight, even though she failed her initial mission as a result, and become one of the most dangerous threats to Stormwolf and the Grand Line as Big Mom's successor. Several other Big Mom Pirates who were relatively minor also have personal duels with the heroes.
In the Super RWBY Sisters series, several characters, be it hero or villain, have been made stronger and better fighters in this universe.
Mario has been made a stronger fighter, to the point that some consider him one of the strongest fighters in-universe and even getting to the point that when he fights with Bowser Jr. in Super RWBY Sunshine, he went easy on the kid to give him a chance.
Jaune, being one of the weakest fighters in the original series, is more competent and a more capable fighter than his canon counterpart. This also is due to the training he received from fighters in the Super Smash Bros roster.
Dr. Toadley has his moment when he binds The Atlas Military and the White Fang in light so they wouldn't destroy Peach's Castle. He tells them that they should settle their differences in the garden.
Weiss is becoming stronger in each story, even holding her own against some bosses. Even Winter is surprised at how strong she's getting. After Weiss obtains her Fierce Deity Transformation, Blake pointed out she has become the strongest member of Team RWBY at this point.
Of all people, the SA-X gets this treatment as it's far more intelligent than its canon counterpart. It's able to use other weapons other than simply destroy things with Super Missiles. For example, it uses a charged-upWAVE BEAM and nearly obliterated SPBRR with it!
Even some of the bosses in SPBRR Fusion get new attacks to make them even more deadly and serious threats.
Any enemy that falls under Calasmos's influence becomes more powerful.
Most of the characters that make an appearance in this story can fall under this trope due to how the author has written them all.
Superwomen of Eva 2: Lone Heir of Krypton: Asuka was the best Humongous Mecha pilot in the original story, but she was still a physically fit thirteen-year-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.
Tattered Capes Under a Shattered Moon: Dragon and Defiant gain unlocked Auras, giving them extra durability and strength on top of what their armor gives them.
Hawkmoth can not only give people powers, but he can also mind control them as well. He also has more direct offensive abilities, like attacking with his butterflies directly, and other energy manipulation abilities, like Playing with Fire, with the caveat that their power can be significantly affected, positively or negatively, by the ambient emotions around him, like how the bravery and outrage of the Parisian citizens weakened his fire powers enough that an ordinary fire extinguisher could put it out. It's also hinted that he has other dark magic which he used to bend Nooroo to his will.
Ms. Bustier is more proactive with her students and was also a previous Miraculous holder.
Chi Chi, rather than being a stay-at-home mother, is an instructor at Kame House.
Max Tennyson was the previous wielder of the Omnitrix in this series. While certainly a badass in canon, he never wielded the watch outside a What If? episode and was considered unstoppable with it. As shown at the end of Changing of the Guard, he still retains some of the watch's transformative properties even after having not been its wielder for decades.
Julie gains Kree StarForce training, a bionic arm, and showcases better unarmed combat skills. And that's before she gets Ship.
In the MCU, the Nova Corps were more of a generic galactic army. Here, their Flying BrickSpace Police status is re-established.
In the final chapter of She Stole My Heart (and most of my valuables), it's revealed that the Masters of the Mystic Arts gave Dipper a Sling Ring after the events of Weirdmageddon, and he's capable of using it too, implying that he'll be studying more eldritch magic.
Thieves Can Be Heroes!: Downplayed with Ryuji. In this story, he has a Super-Speed Quirk. While Ryuji can run extremely quickly for short bursts, his Career-Ending Injury effectively cut the power and duration of it in half, forcing him to use it sparingly lest his knee give out on him.
Thousand Shinji: 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 Warhammer 40,000, 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.
All Might ate the phoenix devil fruit, not only healing him but making him stronger than ever. Considering how in canon his heavy injuries are what took him out of heroism, this is a massive upgrade.
Muscular was given a shock absorption quirk, making him far tougher.
Mirko ate the light devil fruit, making her one of the most powerful lightning bruisers in the story, able to casually smack around Shigaraki and Gigantomachia.
All For One stole (or at least copied) Overhaul, Stress, and Erasure.
Izuku ate the Soul Soul Fruit and determined that by having his homies inhabit them, he can feed devil fruits to his weapons and still utilize them the way Funkfreed was used. He's actually so powerful that All For One summons his entire army just to deal with him.
Izuku turns into a cursed spirit. How not only he has the Super-Strength of his canon counterpart, he also has Shock and Awe abilities, Telepathy, a Healing Factor, is The Ageless, has Super-Speed, Voluntary Shapeshifting, can infuse objects with cursed energy, No Sells all quirks, and doesn't appear to have a stamina limit. He is better than his canon counterpart, and ranked a Special Grade curse that can keep up with Sukuna for a damn good reason.
Tokoyami can infuse Dark Shadow with cursed energy, which enables it to eat curses.
Shigaraki is a Curse user on top of having his quirk and even brings a Special Grade curse to USJ as opposed to a Nomu.
Played with Katsuki: he gets cursed energy and is trained in a weapon, but while in Jujutsu Tech he cannot use his quirk which makes him the weakest of his peers, even if he has more abilities than his canon counterpart (especially since Quirks do not work on curses).
To Hell and Back (Arrowverse): The basic premise of the story is that Barry, Oliver, Kara, and Kal-El all spent a decade on Lian Yu and then with the League of Assassins. Oliver, no slouch already, becomes even better than his canon self, Barry becomes an Empowered Badass Normal and even more of a Badass Bookworm, and Kara undergoes Boxing Lessons for Superman that, combined with her Combo Platter Powers, allows her to curb-stomp her way through Unskilled, but Strong Kryptonian mooks (though she does have trouble with the most powerful villains, such as Astra and Grodd).
Tomica Hero Rescue Pups: Where do we start? The PAW Patrol pups start by defeating several Axto when in their own show, the pups barely ever engage in combat. And this badassery only escalates from there, seeing that the author repeatedly has them reference Star Wars and 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 Death Troopers.
Total Drama Infinite: Downplayed with DIO, who has the same abilities he had in canon but lacks his canonical weakness to sunlight. This is primarily to justify him competing in the show to begin with, as he would otherwise be unable to participate in challenges that take place during the day.
Unfamiliar: Almost every canon character from The Familiar of Zero (but especially Princess Henrietta) gets a massive competence boost and a power upgrade. Considering that they're expected to cope with One-Man ArmyAlex Mercer, this is perfectly understandable.
Unlimited: Izuku, Mei, Dabi, Stain, and Bakugo are all "Anomalies": people with abilities far beyond human in a way unrelated to their Quirks. Mei creates technology at least half a century ahead of its time, including a self-evolving AI. Dabi seems to be undead, has Super-Speed, and creates flames even hotter than Endeavor's. Izuku is basically a proto-Saitama and can go toe to toe with All-Might. Stain is even faster than Izuku. And Bakugo, who seems to have "awakened" after meeting Izuku again, managed to beat the entirety of Class 1A by himself with only minor injuries to show for it and later almost beats Shigaraki and Toga, only losing when Dabi steps in.
Vacation means Chaos: Black Widow is much more dangerous than her movie self. Not only has she taken the same Super Serum as Captain America, but she's also been an assassin since World War II, putting her more in line with her comic book self. Xander notes that even Buffy probably couldn't take her in a fight.
Venus Flash does this to Hikaru Sorano: in Codename: Sailor V she's merely Minako's Muggle best friend, but here it turns out she's actually an amnesiac Cutey Honey, and as soon as she remembers she becomes a force to be reckoned with.
Shampoo was already a fairly impressive fighter in Ranma ½ canon, but widely considered inferior to the male fighters. After eating the Rabbit-Rabbit Zoan Devil Fruit, she gained a drastic increase in Super-Strength and Super-Speed, making her on par with her beau, Ranma Saotome.
Downplayed with Nabiki Tendo; a strict noncombatant in canon, after the 6th chapter, Ranma has resolved to start training her in martial arts so that she can at least defend herself if need be. Then played fully straight later on when she acquires a Mythic Zoan Devil Fruit, one of the most powerful non-Logia varieties of Devil Fruit, and becomes a superpowered badass in her own right.
Kodachi Kuno in Ranma ½ was largely seen as a joke, only remotely dangerous to Ranma because in their only ever official duel, he was fighting under the rules of her style in a formal match and was severely sleep deprived. In this fic, she grows into a legitimately dangerous martial artist, replacing her gymnast's ribbon with a Whip Sword and pistol and fully embracing her Combat Pragmatist tendency, such as an arsenal of various rose-based grenades.
Ukyo Kuonji was hardly the most intimidating foe in Ranma ½ canon, with only Ranma's reluctance to fight his long-lost friend keeping him from stomping her effortlessly in a few minutes. In the fic, she grows into a genuinely badass martial artist, and even manages to get a better knack on fire ki techniques than Ranma does.
A villainous example is Eldrago; in One Piece: The Movie, he was basically Buggy 2.0; a Normal Fish in a Tiny Pond who was only a threat in the East Blue because of his one-trick Devil Fruit ability, and because he was facing a Straw Hat Pirates crew that only numbered Luffy, Zoro, Usopp, and Nami. In this fic, he's much smarter and stronger, even having made it into the Grand Line as a believable threat. He shows intelligence enough to be able to identify the rare "sea mirage" surrounding the Lost Island, is capable of using his Scream-Scream Fruit to fly as well as shoot energy blasts, and is fast and strong enough that Ranma resorts to using the Hiryu Shoten Ha to defeat him, rather than simply punching him out.
Blake now has the 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 Confusion Fu and, in some chapters, borrows her mother's railgun.
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 Bare-Fisted Monk who uses Ki Manipulation.
Over in Lucina Reacts, Kellam is turned into The Ace, 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 Homura Reacts, Hitomi is turned from a rather average Ojou to a Lady of War capable of taking on Sayaka and Kyoko on a two-versus-one fight and winning with her bare fists.
Witches Rangers and the 141: General Shepard was a pretty old badass who was able to hold his own in a fistfight between Price and Soap. In this alternate final encounter, he is still able to kick the asses of the previous two, the still-alive Ghost, Roach and a de-powered newcomer, Gertrud Barkhorn.
In WonderShock, Alice gains Plasmid abilities throughout the course of the story and the ability to bring pieces of Wonderland into the real world thanks to being injected with ADAM back when she was at Rutledge, all of this making her one of the most dangerous people in Rapture. In the games, while she was a tough fighter, that was only while she was in Wonderland. In the real world, she could easily get knocked out by any grown human.
YuYuGiDigiMoon: Many canon characters are given power-ups, such as the Digimon Tamers receiving beast powers based on the Four Chinese Symbols and the Sailor Senshi receiving the mysterious Valkyrie forms.
dials it up as Samus becomes a Kamen Rider at her own right as Kamen Rider Huntress after Kuroto Dan gives her a Mighty Action X SP Gashat and Gamer Driver.