Deadly Upgrades in Anime and Manga series.
- Attack on Titan reveals that consuming the cerebrospinal fluid of a Titan Shifter allows someone to become one themselves. Unfortunately, once this happens, they have only 13 years left to live. Their human bodies gradually break down until they die, complete with Blood from the Mouth.
- Guts from Berserk has the Berserker's Armour, which draws out the full physical strength of the wearer. However, the armour also draws out the Superpowered Evil Side of whoever wears it, and while the wearer can ignore pain, this is a double-edged sword, since the strength of whoever wears the armour will badly damage their body. Also, the armour mends broken bones by piercing through flesh with spikes. This led to the previous owner dying of blood loss after every single bone in his body was broken.
- Bleach:
- Ichigo is able to throw around massively powerful Kuroi Getsuga Tenshō (energy blasts), but doing so too often risks losing his personality to his Hollow side. He can allow his Hollow side to come out in times of distress, whose violence and power is usually enough to annihilate any opponent. After training with the Visored, he can even do so without going evil, but only for eleven seconds.
- Later, he eventually transforms into a powerful humanoid Hollow, capable of defeating Ulquiorra easily. However, evidently he goes completely berserk, and temporarily gives in to his Hollow side.
- Ichigo eventually learns the Final Getsuga Tensho, the final form of his zanpakuto which surpasses even his Bankai. He puts it to use in his final battle against Aizen, allowing Ichigo to defeat him. The downside of this power is, once he uses it, he loses his Shinigami powers permanently.
- Meanwhile, Ishida's final "upgrade" is one-use-only. He removes his 'Senrei' gloves, which make it more difficult to collect spirit particles- therefore someone who can collect the normal amount of particles while having the glove on has reached the pinnacle of Quincy power. When the gloves are removed, that limit is removed, so a much greater amount of particles can be collected. However, this amount is far too much for his body to handle, so his body seals his powers altogether. He gets his power back later, though, by pushing himself to exhaustion so that being shot near the heart reopens the paths to his power. This leaves him with a Quincy "cross" shaped scar where the arrow struck.
- Cirucci Sannderwicci gains the ability to bypass her released form's drain on her spiritual energy by discarding her wings, enabling her to use a large energy sword from her tail at the cost of never being able to use her wings again.
- The ultimate technique of Komamura's clan, the Human Metamorphosis technique, temporarily grants them an immortal human body. To perform the technique, they have to cut out their own heart. It, too, is one-use only, leaving the user a mortal non-anthropomorphic animal.
- Brave Command Dagwon has Daidouji En becoming Super Fire Dagwon only 3 times due to this. That form, while immensely powerful, requires a burst of energy from the Dagbase to even start the combination and is basically the equivalent of one person controlling two bodies - it eats up the user's stamina like nothing else. He's tough and a walking embodiment of willpower, but it still left En in a hospital bed after each use.
- In Ceres, Celestial Legend, the villains have developed some sort of serum to activate/boost the powers of potential ten'nyo, but once someone is injected with it their body begins to break down,a process that seems to be accelerated by frequent use of ten'nyo powers.
- The anime Claymore almost entirely revolves around the caveat that when the series' eponymous half-demons overclock their powers too far they turn into monsters far more dangerous than those they were created to destroy; some of the more powerful of these 'awakened ones' are the primary villains of the series.
- However, Claymores who have gone past their limit and managed to return to normal are able to do so more easily, allowing them to use more of their power, provided they don't go TOO far past their limit. However, it's theorized by said Claymores that they may still be awakening because of it, just very, very slowly.
- D.Gray-Man: Every exorcist has a synchronizing rate with their empathetic weapon. If they force their Innocence to go over this rate, they can gain a power boost but their bodies break down and they suffer a Heroic RRoD.
- People who possess the Death Note in the anime of the same name can give up half of their remaining life span to gain the ability to discover the true name (which, by the rules, they need to know to kill a person) of anyone whose face they can see. An even larger downside is that if they lose their Death Note, they lose the power— but also the half of their remaining life they sacrificed. If they find their Death Note again, they have to sacrifice half of their remaining life again to regain the power, meaning they'd only have 25% of their original remaining life span left.
- These pop up fairly often in Digimon:
- In Digimon Adventure, when Greymon was pushed by Taichi into evolving, he changed into the dark SkullGreymon, a mindless monster. When he evolved "naturally", he became his true Perfect form, MetalGreymon.
- Takato in Digimon Tamers had a similar experience: When Beelzebumon kills Leomon, Takato's rage and grief is so intense that it corrupts WarGrowlmon's evolution and he becomes Megidramon, which would be fine, except Megidramon's power is so great, that it begins to destabilize the fabric of the Digital World. It's not until Takato gets a hold of himself that Megidramon devolves back into Guilmon, and together, they Bio-Merge Evolve into Dukemon/Gallantmon.
- In Digimon Frontier, the Beast Spirit evolutions ended up being Deadly Upgrades in a sense because the kids couldn't control the power at first and went berserk, wrecking areas and nearly killing each other. Of course, they eventually got over this problem. Only Zoe and Koichi were able to control their Beast Spirits right away (in Koichi's case, when he gained his true Spirit forms).
- Digimon Data Squad and its associated tamagotchi introduces Burst Mode, a Deadly Upgrade version of Season 2's Mode Change. In the tamagotchi, if the Digimon runs out of "Burst Points," it dies. In the anime, Masaru combines Takato and Taichi's mistakes, and mis-activates Burst Mode, changing his partner ShineGreymon to Ruin Mode, who quickly ran out of energy and died. Though, since the minions of the arc's Big Bad died first, he got better thanks to Resurrective Immortality.
- In the Digimon Xros Wars manga, MachLeomon upgrades himself with the Abyss Truffle, which an elder Mushmon explains to be this. The Abyss Truffle gives MachLeomon both a Power High and a regular high along with his new form, but would have killed him had he not been finished off by Shoutmon X3 first. If he'd been weaker, using it would have killed him instantly.
- Dragon Ball:
- The Kaioken technique introduced in Dragon Ball Z supposedly risked permanent damage to Goku's body whenever he used it — especially when he overclocked it. However, thanks to My Kung-Fu Is Stronger Than Yours, by the time he's fighting against Frieza, he can multiply it by twenty-fold with fairly limited drawbacks. By Dragon Ball Super, Goku learns to combine Kaio-Ken X 10 with the Super Saiyan Blue form, but the first time Goku tried it, it was still a work in progress and initially only had a 10% success rate, with the other 90% spelling severe injuries or even death, and even when it does succeed, it can leave Goku unable to use his ki afterwards.
- Super Saiyan 3 is another example. A few minutes of use drained Goku (who was dead at the time, but who was given 24 hours of life force so he could visit his family) of about 12 hours of his life force, and Gotenks, who burned out his 30-minute fusion in 5 minutes. Goku eventually manages to mostly iron out this flaw, but by the time he does, Super Saiyan 3 has become So Last Season.
- Brought up once again in the Future Trunks arc of Dragon Ball Super. It's revealed that the Kai's Fusion earrings are only permanent for Kais. For mortals, the fusion lasts 1 hour (which was the real reason they defused when absorbed by Super Buu). Super Saiyan Blue Goku and Vegeta use them to form Vegeto Blue, but the combination burns so much energy that the fusion lasts only about 5-10 minutes.
- Also from the Future Trunks arc. The fusion between Goku Black and Zamasu is literally a deadly upgrade for the latter. He is immortal, but the other half is a mortal. By fusing with him it means that his body is now half-mortal, thereby making him mortal and finally killable - albeit insanely powerful and still nigh-invulnerable.
- Dragon Ball GT reveals that by taking control of the transformation into an ape, a Saiyan can reach Super Saiyan 4, which Goku and Vegeta can maintain without exhausting themselves. However, the real problem comes when they perform a Fusion Dance into Gogeta against Omega Shenron, who has enough power to waste their galaxy if he wanted. Gogeta can use both Goku's and Vegeta's deadliest attacks as one, the first hit knocking out Omega Shenron's stolen Dragon Balls, and the second would've killed the weakened Syn Shenron...but he's too much of an idiot clown to do the job soon enough. Instead, he forgets the fusion will only last 30 minutes, and wastes precious time screwing with the dragon on cheap parlor tricks.note When Gogeta does try to execute the final blow... the fusion comes undone... with less than ten minutes elapsed. And they pay for it...
- Subverted in Dragon Half. Mink's power grows constantly when she passes her metamorphosis, due to being a red dragon/human hybrid. However, if she achieves her maximum might and completes her metamorphosis, a prophecy states that "a black monster shall appear". A magic bracelet allows her to stop her power development at will, but against the stronger enemies she keeps facing, she is forced to unlock more potential. When she finally unleashes all her power to save her true love, the transformation comes, and the black beast finally is shown in front of them all. As a tattoo on Mink's butt.
- In Fairy Tail, Natsu consumes the Etherion magic absorbed by the Tower of Paradise. This brief and HUGE power boost gives Natsu the edge he needed to give the fake Big Bad Jellal a beatdown. But at the start of the following arc Natsu suffers narcolepsy due to consuming non-fire related magic.
- The anthology Flesh-colored Horror includes a Junji Ito tale called Dying Young. The premise involved a mysterious contagious symptom that makes girls incredibly beautiful, but eventually causes the girl to drop dead in a couple months.
- Edward uses this in Fullmetal Alchemist. After receiving a massive injury during a fight, he uses his soul as a mini-Philosopher's stone, stopping the blood loss in exchange for a few years of his life.
- Toward the end of the Fullmetal Alchemist (2003) anime, Al becomes a Philosopher's Stone. After that, any use of alchemy costs him a piece of his body.
- The Griselda and Libertus Hyper-Zoanoids are this in Guyver. Libertus are designed to rip through other Hyper-Zoanoids like tissue paper while Griselda can, at short ranges, over-power the telepathic control of a Zoalord. However to power those abilities they need to spend most of their time in nutrient tanks because there's no other way to absorb enough energy and even with that the stress on their systems is slowly killing them. (Predicted survival time is about two years).
- Hellsing:
- Alexander Anderson uses the Nail of Helena on himself and becomes a plant-thing far more powerful than his normal self but using it requires him to stab himself in the heart.
- Likewise, Dark Walter is vastly superior to his elderly, human self in terms of speed, dexterity and skill (he's able to slice a skyscraper in half at one point). But his endurance for prolonged combat is quite poor as he quickly develops an Incurable Cough of Death very soon after engaging Alucard in battle, due to the fact that his body is breaking down because of the Doctor's hasty surgery.
- In Hunter × Hunter, Nen is an example of Conditional Powers. The greater the restrictions placed on a Nen user, the greater the power. Main character Gon crosses the Despair Event Horizon during the Chimera Ant Arc and, in his own words, "uses everything" to make himself strong enough to crush the one who pushed him over the horizon. At the cost of never being able to use Nen again and an extremely shortened lifespan, he is temporarily aged to adulthood and gains Nen that rivals the Chimera Ant King's.
- Kurapika also has a similar form of this with his own contract, every time he uses emperor mode, which makes him a master of all 5 Nen Types and essentially a god, each second he spends in the form shaves weeks off of his life, and if he were to use it for so long, he'd eventually die with how much of his life is cut off.
- Inuyasha's transformation into his full-demon form. His demonic blood devours a little more of his mind every time, so his demonic form becomes more and more uncontrollable. When he first transforms, he sounds like Inuyasha on a really bad day, but by the end of the series, his full demon form is incapable of speech and Kagome is unable to snap him out of it.
- And as an inversion, he can also transform into human form during the nights of the New Moon. What makes this a "Deadly Upgrade"? Simple; in human form, he loses all of his demonic powers, meaning he's easy prey for any of the demonic enemies he's made in his life...or, indeed, any true demon that realizes what he is, as half-demons are almost universally despised by their full-blooded kindred.
- Furthermore, he only transforms when facing down enemies it would take him literally seconds to kill with full power. These episodes are usually both awesome and frustrating. His human form can sometimes fall into Not Completely Useless as well, as being a human allows him to circumvent and No-Sell things that would be dangerous or otherwise lethal to anyone with demonic blood, such as the demon purifying barrier of Mt. Hakurei. He's still got all the disadvantages of being mortal, but it's saved his bacon more than once.
- And as an inversion, he can also transform into human form during the nights of the New Moon. What makes this a "Deadly Upgrade"? Simple; in human form, he loses all of his demonic powers, meaning he's easy prey for any of the demonic enemies he's made in his life...or, indeed, any true demon that realizes what he is, as half-demons are almost universally despised by their full-blooded kindred.
- JoJo's Bizarre Adventure has a few. One of the most notable is in Part 2: Wamuu's final attack, "Converging Squall", draws air in and out of tubes in his chest, creating razor-sharp winds that hit everywhere around him. However, the friction created by this attack slowly tears his body apart from the inside. Wamuu only dares to use it against Joseph after already losing his arms and taking a Hamon blow to the chest, which will kill him anyway if he doesn't finish the fight in minutes.
- In Kenichi: The Mightiest Disciple, there are two kinds of aura used while fighting: Dou (letting your anger burst out) and Sei (keeping a calm and level head). It's possible to combine the two for more power, but doing so rips apart the muscles and puts heavy strain on the mind. Of the two who've used it, one ended up in a wheelchair. The other one died, but for unrelated reasons.
- In Kill la Kill, protagonist Ryuuko's sentient uniform, Senketsu, enhances her physical strength, durability and agility to superhuman levels, but constantly drains her blood to the point of unconsciousness, until she stops subconsciously rejecting the embarrassingly Stripperiffic outfit at which point the disadvantage is negated.
- Antagonist Satsuki gains the same powers but is able to avoid this drawback due to knowing how the godrobe works and having no shame. Later in the series however we learn that using the godrobe for long periods takes an enormous toll on her health which she has been suppressing by sheer force of will.
- In the final episode Senketsu absorbs the power of "Absolute Domination" becoming supremely powerful at the cost of overloading and being destroyed shortly afterwards.
- The lead character of Lyrical Nanoha has a tendency to do things that are really bad for her, especially in the second series. This goes from using the dangerously explosive Cartridge System to using her Wave-Motion Gun's full-power form, Excelion Mode. It's revealed in the third series, Magical Girl Lyrical Nanoha StrikerS, that at some point during the Time Skip this all caught up with her, and what should have been a minor injury in battle caused such extensive damage that she had to spend months learning to walk again. She later has her Excelion Mode replaced with a weaker Exceed Mode, which is a more traditional Super Mode. At the end of the series, however, she deploys a new Blaster Mode, which causes direct physical damage to herself and her weapon as a result of drastically boosting her power. Of course, by the time she receives this, she already has a known tendency to use techniques and upgrades that pushes her body to the breaking point, so instead of telling her not to use it, her long-time partner tells her not to overuse it.
- In the anime adaptation of Magic Knight Rayearth, Alcyone tricks Ascot into giving this to one of his pet monsters. It hugely increases its power and freezes the whole landscape, but before long it turns it into a small iceberg with Power Incontinence and it eventually shatters. Ascot is not happy.
- In Mahoromatic, combat android-turned-maid Mahoro has an Ultimate Attack that is actually fueled by her life-force, so every use of it shortens her already brief lifespan.
- MegaMan NT Warrior: The Rockman.EXE anime series did this in their final two seasons, with a twist - Rockman didn't control his transformation, a child named Trill did. Sometimes this worked out, like when Rockman was fighting the very giant Cyber Beasts he was drawing his transformation from; and sometimes it didn't, forcing the other characters to devise a complicated plan to capture him and settle him down which usually failed several times.
- The parallel game, Mega Man Battle Network 6, played with the same mechanic. In battle, you can take the beast form for three turns, after which you drop into a weakened, untransformed state. Of course, you can do it again, which puts you totally out of control and attacking randomly, and if that doesn't win you the battle, you go into a state so tired and weakened that you have to continue the battle at a pretty significant disadvantage. Of course, it doesn't stop the writers from arranging chapters where Mega Man is forced into uncontrolled transformation and you have to lug some other character over to put him down and get him back to normal.
- In 4 and 5, the player can gain certain "Dark Chips". They are a variation of normal chips (there's Dark Fan, Dark Vulcan and so on), but with immense power and ability to change the tide of a fight. There are, however, two drawbacks. One is that every time Mega Man uses the chip, his HP lowers by 1 permanently. Also, the more he uses Dark Chips, the faster he will be placed under "Dark Mega Man" state. He becomes a super-powerful rampaging machine that randomly uses Dark Chips, moves chaotically and doesn't stagger when being hit, but he also slowly loses HP until he reaches 1, at which point he goes back to the normal state. The only saving grace for 4 is the ability to have multiple playthroughs, so you can recollect HP upgrades and basically negate the HP downs. It's made a bit better in BN5, where you sacrifice a chip of a certain type to go into a cross form, but using them regularly will permanently shave 1 HP off your max limit per use.
Later on, Mega Man gets the ability to do this with Dark Chips. Chaos Unisons (as they're called) allows Mega Man to use (most) effects that he can use in a regular Cross, with the addition of being able to use the Dark Chip sacrificed as a Charged Attack. Fail the charge, though, and Dark Mega Man will show up— on the enemy's side. In addition, you only have the ability for one turn, the failure window for the charge doubles each time you use the Dark Chip, and you lose the ability to use the corresponding normal Cross for that battle. And then you realize the charge releases instantaneously if you let go of the fire button while the game is paused, and you can see what state the charge is in...
- In Mobile Suit Gundam: The Witch from Mercury, this is the signature trait of Gundams in the show's universe. Gundams can hook directly into the bodily systems of their pilots through Permet, which vastly strengthens the suit, improves overall control, and allows for the use of Attack Drones. However, doing this also places an immense strain on the mind and body of the pilot, risking "data storms" that ravage their physiology. Permet Score 2, the lowest score to show off the signature Volcanic Veins, leaves its users pained and hyperventilating, 3 is even moreso, and 4 has been known to kill its users or disable them for life in a matter of seconds, even if they've been artificially enhanced to take the strain. Consequently, the technology is banned, and though some terrorist groups or blacksite companies do make illicit use of it, the pilots are very much aware that their days are numbered. The main Gundam of the series, the Aerial, is the sole exception to this rule, able to go up as high as Score 8 without harming the pilot in the least, which unlocks a mess of other abilities other Gundams can't even approach. Unfortunately, the way it gets around this problem is... questionable.
- My Hero Academia reveals that One for All is this for Quirk users. Oh sure, they can accept without any issues and combine it with their own Quirk, but One For All doesn't just take the Quirk inside itself, it also puts incredible strain on the user's body that burns them out. Sadly, no one had an inkling until the fourth user spent twenty years as The Hermit trying to strengthen the Quirk and he found his life coming to a premature end and necessitating the transfer of the Quirk, and it wasn't until All Might did serious research that the vestiges within One For All put it all together. The only reason All Might and Izuku could use it to its full potential is because they were Quirkless, thus they could handle it and make it their own without having their life force sapped. What makes this even sadder is that Quirkless could be gone within a generation, and even if that didn't happen, they could never handle all of the power One For All has accumulated over the years, thus Izuku might most likely be the last holder of One for All.
- Almost every extremely powerful technique in Naruto is some version of this.
- The various stages of Naruto's Jinchuriki transformation, from Versions 1 and 2, to Partial Transformation, to Tailed Beast Mode all involve the Fox's influence gradually taking over Naruto's mind, body, and soul. If he goes past the 4-Tailed form, nothing but the words of encouragement from his father and mother can save him from the Fox's wrath. This also lessens Naruto's lifespan, not that that matters when he's the descendant of a clan known for its natural longevity. Naruto eventually tames Kurama and gains access to five minutes of using Kurama's maximum power.
- Naruto's upgraded Rasengan, the Rasenshuriken, is basically a magical fletchette bomb that attacks targets at a cellular level, inflicting massive and very hard-to-heal damage. Unfortunately, since it's held in the hand, it does this to the user as well. Naruto removes this weakness by perfecting the technique to the point where he can throw it, getting it far enough away from himself that he isn't hit by it.
- Tsunade possesses a technique that allows her to instantaneously regenerate by speeding up her cell division which means it also shortens her lifespan. She is also a descendant of the Senju/Uzumaki clans, so how much this actually matters is currently unknown.
- Naruto also has Rock Lee, whose power revolves solely around the Deadly Upgrade, in that he can open up certain chakra gates to gain large power boosts at the expense of damaging his body. The more gates he opens, the more injured he becomes, and if he were to open up all gates, he would become extremely powerful for a short time and then die.
- Might Guy uses all Eight Gates at one point, giving him strength and speed surpassing even Tailed Beast Mode Naruto only to collapse into a pile of ash and bone fragments once all his energy reserves are used up. The end result was avoided with Naruto's Healing Hands, but even his powers couldn't save Guy's leg.
- Choji's Three Colored Pills each give as successive boost in chakra, but burn out the user's body. The final, red pill instantly burns all the fat from his body and converts it to energy, but nearly kills him in the process. It would likely be fatal to anyone who's not as fat as he is. The pill also causes the user's cells to break down. When he takes it, he nearly dies and is only saved by intensive medical care and medicine from the Nara clan.
- Simply implanting Hashirama Senju's cells into a person's body can grant them enhanced regeneration and sometimes even the ability to use his Wood Release techniques. However, the cells can grow explosively if not properly controlled, transforming living flesh into a tree.
- The Mangekyo Sharingan will eventually render its user blind and result in extreme fatigue. Excessive use of Amaterasu can cause the user's eye to bleed. Sasuke was nearly rendered blind after he used it liberally in a misguided Roaring Rampage of Revenge. The only fix is to take someone else's Sharingan and implant them as your own.
- Izanagi will grant the user a moment of Nigh-Invulnerability, but permanently blinds the Sharingan used.
- Orochimaru's Curse Seal allows the person to use more chakra, and increases their attack power, but using it for too long will corrupt them and the seal will completely take over. Sasuke was unusually capable of controlling this and the otherwise unstoppable transformation of the person from whom the Curse Seal originated. But now Sasuke seems to have lost the Curse Seal altogether in his fight with his brother.
- In the fillers, Kagerou's Ephemeral Vengeance technique seemingly shortens her lifespan, even though it is not what kills her.
- Pain (Nagato) used the Demonic Statue to suck out the souls of Hanzo's men, which emaciated his body. Later, Pain's jutsu that destroys much of Konoha shortens his lifespan. Even just maintaining his Hive Mind and using any of his jutsu wreaks havoc on his real body. According to Konan, he's in danger of dying due to overexerting himself in his battle with Naruto. This might be why he follows "Madara" despite his own incredible power. Then he uses a jutsu to Disney Death revive everyone he killed, and this ages him to death. He only gets to revitalize his body after death in Edo Tensei, using the Preta (Hungry Ghost) Path's powers to suck in Killer B's Version 2 chakra, reversing his transformation.
- Negima! Magister Negi Magi:
- Negi learns a Black Magic version of this. He gets to equip spells to his body to boost strength and/or speed, depending on what he equips, at the cost of damage to his soul. The arc's Big Bad refers to it as "magical doping".
- His master later reveals that it's turning him into a demon. He is almost eerily nonplussed by that revelation, something he handwaves by pointing out that, technically, his master is a demon, and she's still a good person.
- Chao Lingshen also has one of these, in the form of magical runes carved on her body that release a titanic magical power when unlocked. However, doing so causes her intense pain whenever she casts something, so they're normally sealed. Akamatsu has stated that it's in some way related to the Black Magic Negi later uses.
- EVA-01 and EVA-02 in Neon Genesis Evangelion were given strength and capabilities in accordance to the Sync Ratio between the pilot and machine, but the higher the values, the more likely that the pilot might suffer the injuries the mecha did, go insane, or get absorbed into the mecha.
- One Piece:
- Tony Tony Chopper (a reindeer who can become a humanoid with the power of the Person-Person Fruit) can access four additional forms besides his animal, human, and hybrid forms with the use of pills called "Rumble Balls". However, if Chopper takes more than two Rumble Balls within six hours, he turns into a mindless hulking monster. Not only is this move dangerous to those around him (due to his mindless rampaging), but it causes internal bleeding (shown by the blood coming from his mouth, despite never being harmed), making it lethal for himself as well. It's because Chopper's Monster form requires massive amounts of energy to keep going, far more than Chopper actually has. In addition, Chopper is essentially unconscious while he's in that form so he can't leave it on his own. After the Time Skip, he learned how to control it, but it still renders him too weak to move after using.
- Gear Second not only drains Luffy's stamina faster than normal, but according to Rob Lucci, it shortens his lifespan by increasing his metabolism. Lucci also states that if Luffy were not a rubber man, his heart would explode if he used the technique. Of course, if he wasn't made of rubber, he probably couldn't do it in the first place. It is likely that similar to Chopper above, his greatly increased stamina after the Time Skip renders these limits moot.
- And way before all that, the Alabasta arc had a very anvilicious parody of this trope in the form of the Kicking Claw Squad. This consisted of four Alabasta royal guards that took an elixir known as the Fatal Fuel. The good part is that it hugely increased their strength, allowing them to break the bracelets on their arms by merely flexing their muscles. The bad part is that said elixir will kill them in minutes. The worst part is that Crocodile exploits this by refusing to fight them, instead retreating to safety and waiting for them to die, mocking them as they die a dishonourable death.
- The lieutenants of the New Fishman Pirates, led by Hody Jones, had pills that gave them incredible strength and stamina, but at the cost of their own lifespan. However, they overdose on the pills to the point that they feel drained the instant the effects wear off. But the real downside comes when it's revealed that one inevitable, irreversible side effect is Rapid Aging.
- Otogi Matsuri: The power granted by the Phoenix-like god named Suzaku is a mystical bow that appears as an extension of Yousuke's arm, that fires arrows of light with the power to kill evil spirits in a single shot. In exchange, Suzaku declares that it will take Yousuke's "future"... meaning that the young man only has a year left to live.
- In Outlaw Star, the three rare Caster Shells, numbered 4, 9, and 13, are so powerful that it also takes away part of Gene Starwind's life whenever he fires one. On a side note, 4 and 9 are considered unlucky numbers in Japanese culture, and 13 is an unlucky number in western culture.
- Break from PandoraHearts has this. The more he uses his Chain, the more it destroys his body...he's already gone blind and has repeated moments of Blood from the Mouth. And yet, he's still extremely badass.
- In the Darker and Edgier Pokémon light novel Pocket Monsters: The Animation, Nurse Joy advises Ash against evolving Pikachu because ones that evolve into Raichu too young end up giving themselves heart attacks from being unable to control their electricity output, leaving them traumatized enough to avoid using their powers entirely and slowly kill themselves.
- In The Prince of Tennis, no one's life is literally in danger, but junior high tennis is taken very seriously, so permanent physical damage may well be equal to death, or even worse.
- One of the earliest example is the Hadoukyuu, a powerful shot that hurts the arm of whoever hits it, as well as whoever is bold, or stupid, enough to try to return it. Used initially by Ishida Tetsu, who then passes it on to Kawamura Takashi, who develops a Dash version which is even more destructive. Then we meet the big brother of Tetsu, Gin, who has 108 levels of this move, of which level ONE is equal to the Dash version. Despite this, Gin loses to a fluke which is widely seen as a cop out.
- Tezuka Kunimitsu, widely regarded as one of the best players in the series has several Deadly Upgrades. The Zero-Shiki Drop Shot and the Invincible Tezuka Zone place considerable stress on his left arm, but he still manages to go into a 37-35 tiebreaker, which is ridiculous for tennis. Later on, these both get upgraded into a serve version, making it literally unreturnable, and a Reverse Zone, which places SIX times the burden on his arm, making it turn a deep purplish hue by the end of the match. Obviously, none of his teammates want him to sacrifice his arm for the sake of victory, seeing that he has a promising professional career in his future. Ironically, in the matches where these are first unveiled, he loses, creating blots on an otherwise perfect official record.
- Another ridiculous technique will ruin one's shoulders, since these players have only hit puberty, and their bodies are still maturing. Yet another one ruins the player's legs, because he's been running at hyper speeds. There's even a player who literally becomes a devil, complete with bloodshot eyes and newly-turned-white hair.
- The most ridiculous example of this trope is the Pinnacle of Perfection, which appears to take the player who achieves this state to a higher plane of existence, but at the cost of losing all of his memories, including those of how to play tennis, rendering this upgrade, at face value, essentially useless. Currently, not surprisingly, the main character is believed to have obtained this state, seeing as how the manga is finally coming to an end. However, it turns out the Pinnacle of Perfection has no drawbacks. It is revealed that Ryoma used it during his match with Kintarou, before losing his memories. Losing his memories was because of an accident, not because of the Pinnacle of Perfection.
- In Puella Magi Madoka Magica, becoming a Magical Girl grants you magic powers, but the more often you use them, the faster you fall prey to The Corruption and eventually turn into a witch. The only way to avoid that fate is to die before it happens.
- Madoka is an extreme example of this, having been repeatedly buffed by a time-travelling Homura to the point that activating her powers even once would cause her to become Godzilla's worst nightmare moments afterward. She eventually subverts this by making a contract specifically to erase all witches from every point in every timeline—including the one she'll become.
- In Rave Master, Sacrifar, the appropriately-named 9th form of Ten Commandments sword bestows the wielder with overwhelming power, at the cost of being gradually consumed by the sword both physically and mentally. At its first appearance, there is quite a bit of Lampshade Hanging over how crazy the man who forged the sword was to put in that form. That said, the sword in question was meant to be used first by Shiba, and Haru was the one who first used Sacrifar in the series; however, after Haru gets a new Ten Commandments meant for him to use, he never uses Sacrifar again.
- A member of the Dragon Race (like Let, Julia, or Jegan) can invoke the great power of the Dragon God, but only by sacrificing their lives to the deity.
- Vampire blood in Rosario + Vampire is this to a human (Tsukune) who receives it. First, it either heals the recipient's body completely or kills him, which already makes it a last resort. Then, it temporarily gives him the powers of a vampire, but after so many uses, the change becomes permanent. Unfortunately, the blood gradually breaks down his body and mind from within, and had its progress not been stopped by a Power Limiter, he would have been turned into a rampaging ghoul. It still surfaces occasionally.
- Sailor Moon can transform into Princess Serenity and blow the Big Bad away with her silver crystal and The Power of Love... but she dies every time from all the energy output.
- In the live-action Pretty Guardian Sailor Moon, she can upgrade to Princess Sailor Moon, in which she is possessed by Princess Serenity and has access to great power. Unfortunately, Princess Serenity is something of a sociopath in that series that doesn't care if she hurts anyone to kill the monster of the day, constantly plays a harp that is actually feeding the energy of Queen Metaria and accelerating the destruction of the planet, summons monsters to beat the crap out of her friends when they try to stop her... oh, and she's perfectly happy to destroy the world and kill everyone on it if anything happens to her lover. Needless to say, this makes Princess Serenity as much of a threat as the Dark Kingdom at the end of the series.
- Cho Hakkai from Saiyuki can turn into a nearly unbeatable super-powered youkai by taking off his power limiters... but runs the very real risk of "losing himself" to the Minus Wave that's brainwashing weaker-willed youkai.
- And the same goes for Son Goku of the same series, much like the Dragon Ball example above— fitting, since they're based on the same character from mythology.
- Upgrading one's Alter Power in s-CRY-ed includes the risk of not only dangerously messing up the user's body, but also eventually draining the user's entire life force. As the series goes on, the Upgraded Alter Power users show more and more damage to their own bodies from continual use. Kazuma and Ryuhou show scars across their bodies where their Alter Powers bond to their bodies, while Straight Cougar is actually unable to walk properly because of how messed up his legs are.
- Using the black blood in Soul Eater is this, as the advantages given by that kind of madness (hardening the blood against injury, not caring about injuries you're receiving or giving because you're out of your mind) are negated by the consequences of doing so too much; the insanity could become permenant. The heroes eventually get around this by being able to control insanity for their own uses, but whether this trick would have continue to work is unknown.
- The Nakatsukasa Purpose is originally seen to be this, but only because Black Star was going about using the Demon Blade mode the wrong way. Until he was beaten into re-thinking his approach, he was told explicitly that over-using the Forbidden Technique would kill him. Once Black Star faces the will inside the Demon Blade and declares that he will strive on the path of warrior to resolve the despair of fallen warriors, he became capable of using the mode without issues.
- Kid's Sanzu Lines are an unusual an example of this. It was implied since this was first brought that he will get the upgrade that would prove deadly to his father. If so, Shinigami is remarkably (well, not so surprising coming from him) upbeat about the prospect. After defeating Noah with this Super Mode, Kid seems aware of the Lines connection to his father, but does not seem to know what effect the temporary upgrade has on Shinigami. Said effect actually entails that once all three Sanzu lines connect, Shinigami-sama -a Great Old One- dies, as by connecting all of them Kid is ready to truly take on the mantle of Death permanently and inheriting his power and position.
- In Tekkaman Blade, D-Boy/Blade's constant transformation from human to Tekkaman and back is disintegrating his central nervous system (the other human-based Tekkamen were also going to die as a result of incompatabilities). When he gets his Super Mode upgrade, in at least the Australian version "Teknoman", the main villain comments that this upgrade causes death within a few months, and it is shown to cause D-Boy/Blade to lose memories as a result of transformation instead of having its previous deleterious effect on the central nervous system.
So long as a Tekkaman was fully converted with an intact crystal then they could switch between forms with no penalty. The problem was that early on in the series D-Boy's crystal was broken and although the shards were placed on Pegas to allow transformation it was flawed and and repeated use of the flawed transformation was what caused nervous system damage to him. It also meant that so long as he used the broken crystal he'd have a time limit before going berserk. It was also true that if a human and Tekkaman plant weren't completely compatible, then they'd eventually die (which is what happened to D-Boy's sister). - In the first Tenchi Muyo! movie, Tenchi Muyo In Love, Achika (Tenchi's mom in the Tenchi Universe continuity) ends up unlocking her Juraian powers, then proceeds to blow it all striking down KAIN. This ended up cutting her lifespan so much that she dies when Tenchi is only 3.
- In the Witchblade anime, the use of Witchblade is shown as too taxing for a human body, and wielder of a Cloneblade sooner or later falls a victim to rapid and irreversible body deterioration ending with spectacular Super-Power Meltdown. In some cases it will also corrode their mind as well. Both original and Evil Knockoffs are Clingy MacGuffins, of course.
- In Yu-Gi-Oh!, the Spell Power Bond can double the attack strength of any Machine-type Fusion monster; however, at the end of the turn in which it is used, it decreases the user's Life Points (which, in GX, where it was introduced, started at 4000, making it much more dangerous than the real card) by the original attack power of the monster. Possibly another example of Explosive Overclocking. Similarly, the Spell Limiter Removal can double the attack strength of all the user's Machine-type monsters for one turn. After which, they are destroyed.
- In YuYu Hakusho, Hiei's Dragon of the Darkness Flame goes given a second use beyond basically an out of control beam attack- Hiei can let it hit him in order to absorb its power. The catch to this powered up state? It leaves him utterly drained and basically comatose for a time. Good thing he's got teammates to look after him.
