- A Naruto/Negima crossover Fanfic, "Broken Faith" by Kur0Kishi has this in spades. Naruto inherited Kyuubi's core and powers before he came into Negima's era, giving him an extended and merged version of the red Kyuubi Cloak and the golden Kyuubi Chakra Mode from Canon manga with awesome horns and chains to boot, rendering him a literal God on the battlefield. The problem? It burns his flesh away every second unless he reinforces his organs liberally with Chakra first, to the point where people start to see his bones if he holds the mode up for anything longer than 5 minutes.
- Doubled in that using the power accelerates the breaking of the seal that's keeping him weak and stuck in Mahora. Sounds good doesn't it? It isn't, if the seal is released in a way it wasn't meant to ( i.e ; Breaking), both him and the tree go up in an explosion powerful enough to kill Divinity, taking everything in radius along with him at the same time.
- Happy Families Are All Alike (A Naruto/Negima crossover) has Naruto himself. He has superhuman senses and is physically outstanding. He has powerful regeneration... but the Kyuubi has, as of chapter 7, firmly planted its feet in the Eldritch Abomination category. And it can tear his flesh apart in his dreams.
- Child of the Storm has Harry who, true to form, finds his powers more of a trial than a blessing, usually because they tend to turn on and off pretty much at random. He is, for instance, often worried that his Super Strength, which tends to activate when he's angry or scared and completely without warning, will lead to him one day shaking someone's hand and crushing their bones to powder. And then there's the Psychic Powers. Though he gets a handle on them relatively quickly after they manifest, he goes through one hell of a case of Power Incontinence.
- Taylor suffers this in The Last Daughter, owing to her nature as a Kryptonian. She constantly fears hurting friends and loved ones with her titanic strength.
- In Kyon: Big Damn Hero, Haruhi realizes her power and nearly goes into a Heroic BSoD when she realizes just how sensitive it is. Yuki helps subvert this trope by becoming a buffer, and Haruhi runs a Memory Gambit on herself to limit herself to more manageable Mind over Matter powers.
- The Harry Potter/Marvel Universe crossover A Third Path to the Future has Melody, a young mutant whose powers change anything she sees into music. While Melody can tell exactly what kind of person someone is by the songs she hears from them, her mind has been so warped that she has no concept of numbers and has little to no social skills. According to Xavier, she's one of the few mutants in The Vault simply because she's incapable of taking care of herself.
- The Three Kings: Hunt: The Mages who get magical powers which can be very powerful but are also very specific and limited; these same powers also cause mages to be hunted down and killed by wizards. Further according to the author not all these magical powers are very useful (for example generating globes of light)
- Shirley Fenette in Justice Society of Japan has technopathic powers and a clockwork body. On one hand, this gives her total control over machines and super-strength. On the other hand she can't heal naturally, frequently suffers Power Incontinence, and has this pink antenna things that make her look like a robot.
- In The Bridge, Aria Blaze manages to sing a melody that calms down the human transformed Kaizer Ghidorah. Pro? She avoids getting killed by Kaizer and siphons a large boost in energy from him that amplifies her own powers. Con? She did it right when another kaiju named Enjin was hunting Kaizer, tracking him via his energy signature. An energy signature Aria now shares, causing Enjin to target her too. Oops.
- In Overlady Jessica is half-incubus, not half-succubus. So if she loses her focus, she'll radiate immense manliness and appear incredibly handsome despite having a voluptuous feminine figure. According to her, it's murder trying to get a boyfriend when her manliness makes them all feel insecure.
- Due to the Halloween spell, Xander and Jenny Calendar gain the Starship Enterprise in Ship of the Line: Humanities Loss. The catch is neither can ever leave the ship. Jenny because she's a furry cat-like alien and would stand out too much and Xander because he's now the ship's Medical Hologram and as such is physically unable to leave the ship.
- Taylor Hebert's new friend in Snuggles the Symbiote is a mutant whose power amounted to super hormones that ruined her immune system and kept medication from working. Luckily, her symbiote "Snuggles" feeds of hormones and can keep her from getting sick, along with giving her the standard Spider-man powers.
- Hawthorne Isley from Deadly Nightshade inherited his mother's ability to secrete toxins by his skin, which knocks out or sickens anyone brushing against him. It certainly protected him from physical abuse when he lived with abusive caretakers, but he had to be homeschooled to not accidentally hurt another child.
- In Le Commencement du Diable Blanc, Remy's explosive power manifests when he's barely a kid and promptly worsens so much he starts suffering seizures. When he was brought to Professor Xavier, the older mutant had to perform Psychic Surgery on the eleven-year-old to dampen his ability.
- In Neither a Bird nor a Plane, it's Deku!, Izuku Midoriya is Superman. Sure, he has every power he could ever ask for, but he can't turn his strength off. He has to treat everything like wet cardboard and he's haunted by the time he nearly killed Katsuki Bakugou with it as a child. Then there's the Sensory Overload he gets whenever he turns on his Super-Hearing.
- In the Assassin's Creed and Temeraire crossover fanfic Trade Winds, William Laurence turns out to have two Assassin ancestors, which allow him to develop Eagle Vision that lets him not only spot the true gravity of his beloved dragon's illness, but also allows him to locate and secure enough of the cure to send home to England's dragons. Hooray! However, his manifestation of the ability also makes him The Empath, which causes him to immediately pick up on the pain, sickness, and suffering of those around him whenever he turns it on... which he also feels. Oh...
- In Fate: Gamer Night Shirou gains a blessing from Lilith that reduces the costs of his various skills and increases the growth rate of sex related skills but he has to have sex daily or the costs of his skills are all doubled. When she upgrades the blessing, Shirou also gains a mana drain ability and further reduction of his skill costs but now going without sex makes skills cost five times as much. And because of Shirou's Gamer Body, he's never tired until he runs out of stamina and Lilith's blessing makes sex cost no stamina at all, leaving him perpetually sexually frustrated.
- My Heroes Reborn:
- Victims of the villain Priestess get access to their past life's memories and skills, and thus, by extension, their past life's personality and habits. 96% of those affected quit the hero life because they weren't warriors in their past lives and lack the drive to continue their hero career. Of the remaining 4%, one fourth of them turn to villainy because their past life was evil. Those that remain still have to deal with having perpetual personality shifts for the rest of their lives.
- Of the five UA students affected by Priestess, the girls got off lightly. Izuku Midoriya, meanwhile, became absurdly overpowered in exchange for his past life's perversion, inability to hit women, and chain smoking. As bad as that is, however, it's nothing compared to Mashirao Ojiro, who got increased martial art skills in conjunction with the worst sense of direction in all of anime.
- Katsuki Bakugou got absurdly overpowered swordsmanship in exchange for alcoholism and the second worst sense of direction in all of anime.
- Servants of Remnant: Since Antonio Salieri is an Avenger, he runs on The Power of Hate. Unfortunately for him, he attracts the Grimm (which are attracted to negative emotions) like moths to a flame, until even he is overwhelmed and almost dies.
- In Red like Blood, Ruby gains vampire powers a la Hellsing, but they're a lot more trouble than their worth. She's prone to Sensory Overload many times since she doesn't know how to work with her enhanced senses, sunlight hurts like Hell, she frequently struggles to keep her bloodlust in check, she now has many razor-sharp canine teeth that freak anyone out when they see them. Really, it's pretty accurate to call her powers a curse.
- In Shazam story Here There Be Monsters, the same magic which makes Billy, Mary and Freddy powerful enough to move mountains or fly into the sun causes them to be eternally fifteen, which makes their lives harder.
- In the Tamers Forever Series, as the vessel of Chaos, Takato is gifted with immense power, but that same power is slowly and painfully killing him from the inside out.
- In Dragon Age: The Crown of Thorns, the dwarven noble protagonist is a Magic Knight because he harbors a tear in the veil. Unfortunately, while he did get some of the spirit warrior abilities form Awakening, this seems to have caused at least as may problems, some of them rather serious.
Ed, Edd n Eddy
- Red Lightning gives us Jimmy, who is completely immortal. Unfortunately, this rendered him unable to sleep or fall unconsious, and did nothing to numb his sense of pain. The poor kid had to stay consious while pulling himself back together as atoms in the air!
- Fate/Harem Antics: Hassan of Serenity is a Poisonous Person. While this makes her very deadly in battle, she can't turn it off, so she has become very lonely. Later, when she gets severely injured, Ayako Mitsuzuri tries to help her, only to be warned that she can't touch her without dying. Fortunately, Shielder is immune to the poison and is able to carry Serenity to safety and treat her wounds.
- Luna Lovegood in When Is It a Contract? can answer any question she's asked directly even if she doesn't know the answer (i.e. "Why are we required to have dress robes?" Or "How can I make sure I have a better year?"). However, since she also doesn't remember giving said answers, she often appears crazy whenever someone asks an indirect question.
- In Found Souls Harry has empathy so strong that he nearly attempts suicide at thirteen to escape from the onslaught of others' emotions. The fact that it includes magical creatures as well as sentient beings doesn't exactly help either.
- Death in On a Pale Horse automatically removes the soul of anyone and anything he makes skin contact with. Though he can put their soul back, doing so is unnatural and thus unbelievably painful (Death describes the agony as beyond mortal comprehension). By his own admission, he hasn't touched another living being in millions of years. Fortunately, it turns out that alternate versions of himself, even ones that are still mortal, are exempt, allowing him to hold Harry Potter's hand.
Hetalia: Axis Powers
- Mistakes uses the common Fanon that the nations can't be killed by physical means and can recover from apparent "death". This isn't necessarily a good thing when the fic starts with China being effectively gang-raped to death and being thoroughly traumatised on waking (particularly since up until it happened to him he thought rape was unimportant and murder actually fun, since human morality doesn't quite work with immortals), and the Koreas trapped in Unit 731, where they get dissected again and again and again ...
- A Type 4 appears in Mad World. Lauren develops a rapid Healing Factor. While normally this would be really good, the sucky part comes in when she's captured and tortured by really sadistic Fae. Her wounds healing just means he can torture her again. He quickly abandons regular physical torture, in favor of doing something where even if Lauren could heal, her injury would only instantly reoccur. Her injuries are later compared to those associated with crucifixion. She, understandably, starts to lose the will to live.
- In Project Delta, Jane's implants. Her Super Senses keep her in near constant pain. She gets constant nightmares from the memories in her implants. And, due to her increased body density, she cannot swim.
- In Prince Charming, Adrien is blessed at birth with the gift of charm... which means that anyone he interacts with is brainwashed into his adoring slave within minutes.
- This is a major theme in The Powers 'Verse, expressed among the characters as 'Downside'. d'Artagnan's empathy is useful on missions, but also makes it hard for him to cope in busy, crowded Paris; Aramis can heal injuries and illnesses but is compelled to do so if he's near the injured party; Porthos is a very accomplished thief because people not only don't see him, they actively ignore him, but the longer he stays hidden the more people forget he ever existed; and Athos is very likely immortal and wil have to watch them all die. Some other Downsides are discussed at different times.
My Hero Academia
- Toward A Bright Future: The main character Y/N's Quirk of seeing the future counts on many levels. She has no control over what triggers her visions, she gets a splitting headache if she tries to tell anyone else anything important that she learns from them, any pain from any injuries that she manages to butterfly away is instantly inflicted onto her, and she has never received any visions of her own future. Other characters have commented that they've never seen a Quirk with that many drawbacks.
- A Green Dragon's Hoard: Izuku has Super Strength, Nigh-Invulnerability, and can turn into a massive dragon. The former two cause him to break a lot of objects growing up, including several cars that struck him when he wandered into the streets. The latter is so big as to be near worthless for most activities. It also paints a massive target on his back for people looking to steal powerful Quirks.
My Little Pony: Friendship Is Magic
- The Powers of Harmony: Rarity's insomnia inspires some of her best work, but leaves her very weak (due to denying her magic font time to recharge). Turns out, Harmony engineered this as part of her master plan.
- Twilight's Power Copying ability works by making her more sensitive to magic, which makes it easier to understand how spells work. However, this also makes her more vulnerable to corruptive magic, which leaves her weak and sick.
- Discord made the Princesses immortal and linked them to the Sun and Moon because he knew that eventually they'd snap from the pressure of maintaining the world and succumb to the Chaos magic inside them. This is what led to Luna becoming Nightmare Moon.
- Within the Tripytch Continuum, A Mark Of Appeal kicks off when a character supposedly "blessed" with ludicrous sex appeal comes to Luna with a simple request: to destroy her mark, magic, or both. (The short version: her talent has been growing stronger as she's aged, starting from simply inspiring look-here-first interest in her classmates. It's currently at the point where it crosses gender and species barriers within minutes, creating infatuation, arousal, and then steadily strengthening both. Anyone she tries to speak with will eventually attempt seduction — or worse — and she can't turn it off.) However, the act of directly changing or destroying a mark is beyond even alicorn magic... With the most recent chapter, it's been implied that the curse may actually be genetic, as her parents appear to have had their personalities consumed by their own talents....
- The Hasbroverse: In a Recursive Fanfiction of The Conversion Bureau, Megan Richards gets transformed into a powerful alicorn by the conversion bureau potion, instead of a "newfoal". That would seem like a dream come true. Unfortunately, the potion also had an added side effect of allowing TCB!Celestia to brainwash her if she gets too close. Megan spends much of the story trying to shield her mind from TCB!Celestia's influence.
- In A Growing Affection, Kohaku's status as a living Perception Filter is this. Her parents forgot her when they went on vacation a couple of times (doesn't help that its a big family), and she gets passed over for promotion because no-one can remember what she did in the Chunin Exams. But as a ninja being functionally invisible and easily forgotten is a very useful ability.
- In Shinigan Naruto gains the Mystic Eyes of Death Perception. While his power has a surprising amount of versitility (such as removing Sasuke and Anko's Cursed Seals with a senbon), for a long time anything he looked at with his Shinigan on would fall apart along the lines. Seeing walls and furniture randomly collapse in pieces freaks Naruto out but seeing people falling apart nearly drives him insane. Naruto had to learn the Bringer Of Darkness technique to temporarily blind himself to save his sanity.
- Quistis in Eroninja has a kekkei genkai much like the Sharingan in that it allows her to learn any jutsu. The problem is that she has to be hit by said jutsu first.
- The Rinnegan is treated as such by both Obito and Sasuke in I Am NOT Going Through Puberty Again!. The plus side: you're practically a god in human form. The downside: shared vision with people in sexually active relationships.
- In Pareidolia, Kyuubi hates his power as The Empath since he can only sense hatred with it. No matter where he goes, all he can sense is hatred. According to him, this is what caused his FaceHeel Turn.
Neon Genesis Evangelion
Percy Jackson and the Olympians
- Hayden from the Percy Jackson fanfiction, Riding the Waves. As a daughter of Thetis, she has water manipulation powers similar to Percys. But her powers as a legacy of Pluto made twice as vulnerable.
- The Bradan Feasa/Salmon of Knowledge in Son of the Western Sea possesses all the knowledge in the world, including being able to see the prophecies of others but excluding exact knowledge of the future, but being unable to use it (due to being a fish) and being sought after to be eaten to gain that knowledge. By the time Percy runs into the Salmon, it is so depressed that it's existence has been almost forgetten and that it cannot do anything meaningful with all of that knowledge that Percy is concerned that it might Fade. When the Salmon tries to convince Percy that the prophecy means Percy would have to eat it to gain that knowledge, Percy states that he wouldn't want all the knowledge in the world, because then what would be the point of traveling?
Phineas and Ferb
- All of the hybrids in Morphic to a greater or lesser degree (it is a Deconstruction after all), but Gabriel, a half-Slugma really takes the cake.
- Doubled. Not only is he half a blob of magma, but if he absorbs mud or stone, he begins to heat and get fire powers, which is awesome ... until you realize that, as his body temperature goes up, major tissue and organ damage would result. He's only (part) human. Special mention also goes to Mia Kerrigan, the Scyther morph, who has bladed arms, lightning reflexes, accelerated growth and is probably the strongest of the cast ... but does not understand empathy, limits or self-control.
- Also of special note is Katherine, who was mixed with a Roselia. She ages even faster than Mia and is considered the smartest and most mature of the hybrids... But apart from the fact that she actually dislikes aging so quickly, she also has roses for hands, which makes even simple tasks like holding a pencil difficult. She also gets tired easily if she's not near sunlight.
- The dampener removal in Poké Wars. Its removal greatly augments a Pokémon's abilities. Unfortunately it is extremely painful and results in Power Incontinence until they learn to control it. Even then, their attacks are always lethal and extremely destructive. It is especially magnified for Pokémon like Heatran or Magmar whose body temperature rises to such an extent that being near them is lethal.
Shin Megami Tensei
Sonic the Hedgehog
- Tails gets infected by Shroud in Sonic X: Dark Chaos, which ends up giving him a Lovecraftian Superpower and makes him immune to the influence of Dark Tails. Except he still feels the corrupting influence of Dark Tails at every moment, and he starts to gain Bizarre Alien Biology by the bucketload. And his temper gives him the chance of losing control of said superpower at any moment - he nearly destroys the Blue Typhoon and devours his friends at the end of Episode 73.
- In Hellsister Trilogy, Kara feels her great powers get her isolated them from normal humans and are a hindrance to have a normal life.
Mentally, she kicked herself. All this incredible power, she thought. The ability to fly faster than light, to exist in the vacuum of space, to pierce the time barrier and reappear whenever she wanted to, and most of the time she took that for granted. No wonder that so often, life was stupid, dull, and boring to her.
No wonder that she'd never really managed to fully give her heart, or her body, to anyone yet. How many potential mates could understand the power and needs of a Kryptonian?
- Superman and Man has Christopher Reeve exchanging bodies unwillingly with Superman. After spending years unable to move his body from the neck down, he can walk. He can walk on the Sun, unharmed. And yet he doesn't care because he wants to go back to his universe and family.
- With Strings Attached:
- John has complete control over water and the body of a winged god; but he also has to eat constantly, has ears so sensitive that he folds up in pain at shrill sounds that don't bother other people, and, worst of all, is no longer human, so he's no longer sexually attracted to human women.
- Paul is so ridiculously strong that he can barely move without causing chaos. He has practiced day and night to get to the point where he can walk around, but he has to keep constant watch on himself, keep his arms at his sides, etc. To revert to his more manageable lower level of strength, he has to explode, creating a large glassy crater and wiping out everything around him. Even at his lower level of strength he has to fiercely regulate his behavior. In neither case does he dare have sex. Oh, and neither of them can go home as is...
- George: He's got a ring that lets him become anything... but it also sticks once in a while, filling him with terror that he might get stuck permanently as something else.
- In The Keys Stand Alone: The Soft World, Ringo discovered during the interim between Strings and Keys that he was also Blessed with Suck, because he had become intensely addicted to his mindsightwhich could not return with him to Earth.
- Bird features this as an ongoing theme; whether it's Mimi, or Elle, or Charnel, or Sveta. In fact, one could argue that every patient in Alchemilla falls into this to some degree.
- Wyvern: Taylor has a very powerful Changer ability, but it's stress-based and not fully under her control — not only does she end up transforming when she doesn't want to (which happens several times), but she has to deliberately recall the pain and humiliation of her bullying in order to change on purpose. Better yet, it's difficult for her to turn human again on command, requiring her to be completely calm and relaxed — something she's really not used to feeling. Further, since Taylor's transformation involves changing size and shape, she tends to shred everything she's wearing when she transforms. She goes through three pairs of clothes the first day.
- In Tales of the Emperasque the Emperor merges with Tarrasque, giving him phenomenal psychic power, resilience and physical strength, but first, he's really, really large, which carries its own batch of problems, and second, a Tarrasque is a daemon in this setting, causing panic and multiple friendly fire incidents nearly everywhere he appears.