A common trait of monsters is the Weaksauce Weakness that allows humans to face them. After all, if monsters are so powerful and scary, how come that they haven't already taken over? Thus, fairies are repelled by iron, demons run away in fear before a drop of Holy water, vampires can't stand sunlight, werewolves only roam when there's a full moon, mages need to utter magic words to cast spells, and so on. Not only monsters have this problem; very often, characters that are too powerful are bound to have a restriction that, if they're villains, gives the Hero a chance against them and, if they're heroes, prevents them from being too boring to watch.
It follows that a villain with a weakness that both the Heroes and audience is familiar with, will instantly become a bigger threat if said character gets it removed. Feel sorry for its enemies if their main strategy is Attack Its Weak Point.
The weakness doesn't necessarily have to be a Kryptonite Factor; it could be a well-known flaw that the heroes always exploit, like a detective that can always be sure that the criminal will leave clues behind or that serial killers always follow a pattern that he can deduce to find them.
A character can achieve this through focused (and generally painful) training, get this status as a side effect of increasing their powers, thanks to magical or scientific experiments, by being Badass or just gifted. To remove a Kryptonite Factor, a recurrent method is exposing to small doses of it, in a similar fashion to characters with Acquired Poison Immunity.
Just to be clear, this trope doesn't cover cases when the author changes the character into not having a weak point it used to have, it only counts when it happens in-universe. It also has nothing to do with heroic Ancient Greek amputees.
Compare with Fight Off the Kryptonite, when the character doesn't lose his weakness but tries to fight it through sheer force of will, and Kryptonite-Proof Suit, where the character takes measures to avoid it. Similar to No-Sell, but instead of ignoring other characters' powers, in this case what's ignored are the natural weaknesses. Adaptive Ability is similar, where one develops an immunity to a weakness after a single exposure. For instances where one never had the weakness in question to begin with, see Fake Weakness.
- A commercial for Nutrigrain breakfast bars had a family of vampires. One of the vampires stated "Ve vere not morning people" until they discovered Nutrigrain bars and showed them sitting at the table in sunlight having them for breakfast.
- The Angels from Neon Genesis Evangelion had a Core that, if destroyed, would mean the Angel's destruction as well. But the eleventh Angel had a body made of nanoscale entities, meaning that it didn't have a core, at least not that the heroes could detect and destroy as usual. It also had an Adaptive Ability that allowed it to learn and become immune to anything that they used against it.
- Saiyans from Dragon Ball Z suffer an agonizing pain when their tails are squeezed. Goku used this against Raditz and Piccolo tried to do the same against Nappa, just to learn that he and Vegeta were immune to this; they claim that only low-class Saiyan warriors are affected by this, whereas they're Saiyan Elites. Goku trained himself to remove this weakness in the past, before his tail was permanently removed.
- In Resurrection F and later Super, Frieza trains for the first time in his life and gains a Golden Super Mode... but because he was impatient and rushed off to kill Goku before mastering it, it practically bled stamina and exhausted him quickly. When he next appears in the Universe Survival saga, he reveals that he's spent his time dead meditating (read: imagining ways to kill Goku) in order to fix that problem, allowing him to hold his own in the tournament.
- JoJo's Bizarre Adventure :
- In Battle Tendency, a Pillar Man who wears a Stone Mask empowered with the Red Stone of Aja will become immune to both sunlight and the Ripple, the only two things that could kill them.
- In both Part 4 and 5 there was a character whose Stand activated after the user's death, and since the only surefire way to destroy a Stand is killing the user, it was impossible to destroy.
- In the world of One Piece, there's a universal rule that says that, if you eat more than one Devil Fruit, you die. Blackbeard has seemingly broken the rule, though no one but him knows how he achieved it.
- Walpurgisnacht from Puella Magi Madoka Magica, the only witch that could exist outside a barrier and therefore wreak havoc on the real world.
- An episode of Pokémon featured a trainer that made her Steel-type Skarmory fight exclusively against Fire Pokémon until it overcame its weakness against Fire.
- Another episode featured another trainer who had his Ground-type Sandshrew repeatedly dive into a pool to help it overcome its weakness against water.
- Another trainer came up with a way to let her Flying Pokémon ground electricity without getting seriously hurt.
- Early on in the second series, Ash taught Pikachu to use the Steel-type move Iron Tail, giving it an edge against Rock- and Ground-types that were immune to its electric attacks.
- In Phantom Quest Corp., Bosco eventually became immune to sunlight through controlled exposure to high-powered UV lamps. Which was done as part of his attempt to give up being a vampire, because he'd fallen in love with Makiko.
- In Monster Rancher, after initially re-merging with his original body, Moo finds himself weak against any kind of light. It's eventually discovered that this weakness came from not using the Final Gate's master program, which involved a Magic Stone. Upon stealing Holly's stone and using it in the process, not only is Moo fully healed and stronger than ever, but he's no longer harmed by light.
- Kingdom Come: It is revealed early on that because of all the yellow solar rays Superman has absorbed at that point, he gained an eventual immunity to all forms of Kryptonite, making him effectively invincible to everything but magic.
- Subverted by The Riddler in the Batman story that established that he's obsessively compelled to leave clues, otherwise he can't successfully commit a crime. The Riddler starts using forms of self-therapy to overcome his compulsion, and eventually manages to steal some jewelry without leaving any riddles. Meanwhile, Batman and Robin keep stumbling across strange people and events, which they end up connecting together to figure out Riddler's next crime. It's revealed when they catch him that Riddler hadn't overcome his compulsion—he started sleepwalking and left clues subconsciously. This realization actually led him to surrender to Batman, because he realized it meant he really was crazy.
- Son of the Sannin:
- In the Naruto canon, using the Mangekyo Sharingan takes a heavy toll on the user's eyesight, and the rest of the physical body when using Susano'o, unless the user gains the Eternal Mangekyo Sharingan by transplanting another's eyes. In this story, Shisui Uchiha undergoes Sage Mode training, and discovers that Nature-based energy allows him to counter the MS's usual handicaps.
- A specific case happens in Chapter 110 when Edo Tensei!Hiashi meets his brother Hizashi. His natural course of action would be to try and use the Caged Bird Sealed, which by then had already been removed from him and the rest of the Branch House Hyugas.
- Hermione Granger The Arithmancer receives a letter of thanks from a curse-breaker who encountered a basilisk that had been deafened and was thus immune to the crowing of a rooster. Fortunately, Hermione's color-filtering goggles allowed the man to resist its deadly gaze and prevail.
- Becoming this is Deacon Frost's goal in Blade. Until he completes the dark ritual, he and his followers have to use a thick covering of sun lotion to survive in sunlight.
- In I, Robot, everyone except Detective Spooner is convinced that no robot would ever attack a human due to their programming. It turns out that the main suspect, Sonny, has a second positronic brain that allows him to understand the Three Laws, but disobey them at will. In a twist, Sonny doesn't murder anyone even with that restriction removed; the only person he killed asked him to do it.
- In the climax of Underworld: Evolution, Selene gains immunity to UV radiation (and thus sunlight) by drinking Alexander Corvinus' blood and becoming a vampire-Immortal hybrid. As previously shown, even the most powerful vampires suffer lethal burns when exposed to sunlight.
- Dracula in Van Helsing displays none of the weaknesses commonly associated with vampires; Anna mentions multiple weapons that have failed to destroy him in the past, he survives being staked through the heart onscreen, and uses a Cross-Melting Aura to destroy the silver crucifix Van Helsing threatens him with. Carl eventually figures out that the only thing capable of killing him is a werewolf.
- Gremlins 2: The New Batch: When the Gremlins break into the genetics lab, one of them mutates into a Bat-Gremlin hybrid. Another Gremlin who recently gained sentience because of a brain potion injects his winged compadre with another mixture that makes him resistant to the Gremlins' fatal weakness to sunlight so that he can go on a rampage in the city. Why he didn't take the potion himself is another matter.
- In Megamind, Megamind creates a new superhero using Metroman's genes. This new "hero", Titan, has the same powers as Metroman. That's why Megamind is shocked to learn that, unlike Metroman, he's immune to copper. In this case, it hints at the fact that Metroman was never weak against copper to begin with; he merely faked it. The weakness is not so much removed as never existed in the first place.
- In Ernest Scared Stupid, trolls' weakness to milk was foreshadowed due to Trantor constantly running off whenever he caught sight of it. In the climax, Kenny realizes the truth and he and the neighborhood kids use it to help Ernest wipe out Trantor's newly raised army. However, during the fight, Trantor channeled the evil spirits of the woods to take on a One-Winged Angel form for a Final Battle with Ernest. When he corners Kenny, he sprays Trantor with milk, to no effect.
Trantor: I've grown too strong for that. Not even milk can stop me now!
- The Yeerks' need to leave their hosts once every three days to absorb Kandrona rays with their real bodies, otherwise, they die of starvation. On their planet, the Kandrona rays are generated by their sun, on Earth they have a secret base with an artificial generator.
- A renegade Yeerk that couldn't afford to go back to the base found a way to survive anyway, by killing and eating a fellow Yeerk every three days.
- In another book the Yeerks found a substitute for Kandrona that they could absorb without leaving the host's body, unfortunately it was highly addictive, hindered their ability to control the host, and could potentially drive them mad, replacing their original weakness with something worse.
- Artemis Fowl: Demons, as a species, are no longer able to use magic after they reach their adult stage, called warping (warlocks are extremely rare, but don't warp). So when the Big Bad starts using magic despite being, in his own words, "such a magnificently warped creature"... it turns out there's an unconscious warlock's spirit inhabiting his body.
- The Terry Pratchett book Carpe Jugulum has a family of vampires whose father has trained them all to be immune to sunlight and to not react to holy symbols or garlic, as one is just a collection of lines and curves and the other is merely a member of the Allium family. This bites back hard at the end of the book, though, when the family can't stop seeing holy symbols everywhere. After all, they're just straight lines and curves...
- In The Dresden Files, the Fomor can use magic over running water due to their natural affinity for entropy magic, unlike demons, spirits, mortal practitioners, faeries, semi-mortals, and quite possibly gods. And yet, it is still possible to use magic on running water itself, but not when, say, on a boat.
- In Harry Potter and the Goblet of Fire, Voldemort uses Harry's blood in a ritual to restore him to power, which also allows him to bypass the Power of Love protection bestowed on Harry by his mother's sacrifice.
- It's worth noting that by removing this one Achilles' Heel, he created a new one which bit him in the ass spectacularly, shortly before the climactic final battle: As long as Voldemort lived, the Killing Curse was ineffective on Harry. In Voldemort's defense, he couldn't see that one coming. Even Dumbledore didn't know for sure.
- Hercule Poirot once faced a killer that he couldn't gather evidence against because he didn't murder anyone, he subtly manipulated people with seemingly innocent remarks to hit their emotional buttons and push them into murdering. Poirot realized it but still was unable to bring the villain to justice, since none of his actions could be seen as a crime, so he broke his moral code and killed the guy, lamenting how that, at the end, the villain even managed to make Poirot himself a murderer.
- Saruman from The Lord of the Rings created a new breed of Orcs after his FaceHeel Turn, the Uruk Hai, that weren't weakened by sunlight, unlike ordinary Orcs. They were also stronger and overall superior.
- Twilight vampires feel a strong, almost uncontrollable urge for blood, the only exception being Bella after her Vampification in Breaking Dawn.
- Trolls in Mother of Learning have regeneration that is usually best countered with fire, but the protagonist encounters a number of war trolls that are magically warded against fire.
Live and learn next time he was using frost traps instead.
- Lestat of Anne Rice's The Vampire Chronicles series does this accidentally. After living several hundred years, he decides to commit suicide by flying into the desert sun. As vampires can't stay conscious during the day, he passes out during the attempt, and wakes up, severely weakened, submerged in sand where he fell after passing out. Although the experience nearly kills him, his body heals into the appearance of a man with a deep, permanent, suntan.
- Portions of the Star Trek: The Next Generation novel "Imzadi" by Peter David take place decades after the events of the series. At the climax, Commodore Data fights Admiral Riker, and when his opponent reaches for the off-switch between his shoulder blades:
Data: I had it removed some time ago, sir. It was becoming a nuisance.
- Given the number of vampires in Buffy the Vampire Slayer and Angel, there's bound to be examples of vampires immune to their traditional weaknesses.
- One involved removing the vampire's heart surgically (which will kill him eventually, but renders him immune to vampire weaknesses until then).
- Another example was when the Fang Gang goes to Pylea, Angel discovers that the dimension's sun doesn't harm him, allowing him to operate during the daytime.
- Dracula went to gypsies sometime in the 1800s and traded vampire secrets for protection from a few vampire weaknesses. Such as now he cannot be killed by a stake through the heart.
- The first Buffy and Angel crossover episodes featured a ring that made a vampire unkillable and featured a fight between Spike and Buffy in broad daylight. Needless to say, it was destroyed soon after.
- Demons in Supernatural are weak to numerous mystical effects such as salt lines, iron, devil traps, holy water, hallowed ground, and the demon-killing knife. The top tier ones, however, prove to be immune to most.
- True Blood: Sookie's blood, because of her fairy ancestry, has the power to give vampires this ability. It's temporary, though.
- One of the characters in Neverwinter Nights is secretly a werewolf, masquerading as a merchant and selling silver artifacts and wolfsbane herb to werewolf hunters. Not only does this keep suspicion away from him, but he also claims that exposing himself to his weaknesses in this way has allowed him to build up a tolerance to them.
- Legacy of Kain:
- Moebius has a scepter that is enchanted to weaken any vampires he uses it against. Raziel is completely unaffected by the scepter due to him being 'remade', and while Kain is initially affected by the scepter, he discovers that he's become immune to its effects when Moebius tries to use it against him towards the end of Defiance (as a side-effect of Raziel ripping Kain's heart from his chest during a previous encounter).
- And in Soul Reaver, the Rahabim Vampires have evolved into amphibians, overcoming the vampiric weakness to water (but losing the ability to resist sunlight) in the process. By killing their leader Rahab and absorbing his soul, Raziel also overcomes this weakness.
- In The Elder Scrolls V: Skyrim's Dawnguard expansion pack, the vampire Lord Harkon intends to create a permanent eclipse to black out the sun, allowing his clan to hunt freely without being hindered by their weakness to sunlight.
- According to lore in The Elder Scrolls IV: Oblivion, the Cyrodiilic strain of vampires long, long ago made a deal with Clavicus Vile (the Daedric Prince of Pacts) that allowed them to decrease or outright lose the weaknesses of vampirism so long as they kept fed (a vampire that has fed in the last day can pass as mortal, take no damage from sunlight, and is only somewhat weaker against fire and as one quest reveals, a well-fed vampire is mortal enough to sire a child the old-fashioned way), at the cost of also downplaying the strengths of vampirism until they go without feeding. Skyrim brought in a similar mechanic for Skyrim vampires without the lore explanation, although in their case sunlight will always weaken no matter the stage it's just increasingly crippling.
- In Xenoblade, the otherwise hard to damage Mechon are easily dispatched by the Monado. This isn't the case for the later introduced faced Mechon, who No-Sell the Monado like any other weapon, which in turn forces the heroes to take them down the hard way. In turn, the Monado later gets a Mid-Season Upgrade which lets it take on faced Mechon with ease.
- Metroids, the recurring enemies that can suck up energy from any living thing in the Metroid franchise, will always have a weakness to cold-based attacks. note In Metroid: Other M, there's an area that is housing altered Metroids that have their cold weakness removed. Adam stops Samus from going into that room and goes in there himself to blow up the sector in a Heroic Sacrifice so that Samus can take down Ridley, a foe she has more experience with compared to Adam.
- In the Wii installment of Punch-Out!!, many opponents cover up their weaknesses during Title Defense. For example, Glass Joe wears headgear to protect his glass jaw while King Hippo wears a manhole cover over his stomach. Special mention, however, goes to Bald Bull. Normally, Bald Bull will instantly be knocked down if he's punched in the stomach during his Bull Charge. In Title Defense? Bald Bull will keep his balance and go right back to fighting.
- The Pokémon Slaking has some of the best stats in the game, comparable to some legendaries, but its ability, Truant, make it only attack every second turn. Yet there are some attacks that can remove or replace this ability, allowing him to unleash his full potential every turn, most likely overwhelming everything that stands on his path.
- In Jade Empire it is brought up multiple times that the Spirit Monk's fighting style has a flaw. The flaw is such that it doesn't really hinder them since pretty nobody can take advantage of it in a meaningful way. The people who observe it praise the Spirit Monk's master for teaching them this way, assuming it's supposed to be a Fake Weakness to lure opponents into a false sense of security. It's not. Master Li deliberately incorporated the flaw so that he could easily kill the Spirit Monk once they had outlived their usefulness. The flaw was designed such that only Master Li could take advantage of it. By the time the final battle begins, Master Li correctly assumes that the Spirit Monk has corrected the flaw in their technique, meaning he can't easily kill them anymore.
- In Donkey Kong Country 2: Diddy's Kong Quest, Kaptain K. Rool's weakness is that the cannonballs fired from his blunderbuss can be picked up and thrown back at him to plug it up. This is not the case for King K. Rool in Super Smash Bros. Ultimate, who can use his blunderbuss to vacuum up cannonballs thrown at him and fire them back.
- The main point of the Ultimate Personas in Persona 4 and Persona 5 is removing the elemental weakness of the party member's starting Persona (in 4, though two members still have a weakness) or, in a downplayed example tripling the Evasion stat against their elemental weakness (in the Golden version of 4, as well as 5). Since being hit by an attack you are weak against gives the attacker an Extra Turn, removing or reducing elemental weaknesses in your teammates should be a top priority.
- In Dark Souls, Gwyn was noted for his vulnerability to parrying; a skilled player could give him a truly dreadful time with it. As the second phase of the Soul of Cinder in Dark Souls III, he can no longer be parried; players have reported hearing Gwyn's battle music go, instinctively going for a parry, and ending up getting torched.
- In Fate/Grand Order, Medb is confirmed to have a weakness to being struck in the head by a thrown cheese, as this was how she died in legend. When you try it, however, she kicks the cheese away, and announces that she's used her time on the Throne of Heroes to train for exactly that. After an animation update, her new Buster-style attack is reacting to a cheese that comes flying at her, and kicking it at the enemy.
- In Fire Emblem: Three Houses, units can learn abilities that cancel weapon effectiveness against them by increasing their Riding, Flying or Heavy Armor skill to the maximum rank. They're also used by some bosses. Certain shields can grant the units the same abilities.
- The Adventures of Dr. McNinja: The evil ninja Frans Rayner initially has a pressure point — when struck there, he is completely paralyzed for a short while. However, Rayner also has enough mental control over his body that, any time his pressure point is discovered, he can change its location. So, no paralyzing strike ever works against Rayner twice. Eventually, Rayner completely eliminates his weak point. He suffers a mortal injury, and survives by becoming a cyborg — in the process, he has the presence of mind to shift his pressure point into one of his fleshy bits that gets cut off.
- Gargoyles: Demona gained the ability to turn into a human during day, instead of turning into stone like her brothers. While she hates humans and therefore hates her daytime form, she became more dangerous by being mobile during the daytime to do as she pleases while normal gargoyles sleep.
- My Little Pony 'n Friends: Ahgg, the witches Giant Spider minion, is extremely ticklish and can be rendered helpless by some light tickling. In "The End of Flutter Valley, Part 9", Hydia gives him a potion that removes this weakness. This becomes an issue for the heroes when they find him guarding the valley entrance and Megan's previous strategy for getting past him — tickling him his legs — fails to work.
- In The Powerpuff Girls, the Rowdyruff Boys' first appearance ended with them exploding just from the Girls kissing them. When they're brought Back from the Dead by Him, they no longer have this weakness, but unfortunately now have an equally pathetic one: the increasing power and size they got from tormenting the Girls is later lost when their masculinity is threatened.
- ThunderCats (1985): Mumm-Ra, the Big Bad, can, for all his strength and dark magic, be repelled if he can be tricked into seeing his reflection. Later on in the show, he loses this weakness and is a significantly more dangerous threat because of it.
- In Young Justice, Superboy can be put into a trance by Lex Luthor with the phrase "red sun", due to him being cloned by Lex. The first time this happens to him, he wakes up several hours after attempting to attack Lex. The second time he tries to attack Lex, the same thing happens; until the rest of the team shows up and it's revealed that keyphrase was removed from his mind by Miss Martian.