13 Powerful Anime Abilities That Are More Like Curses

Inumaki inherited his clan's signature ability - Cursed Speech. By infusing his words with cursed energy, he can literally speak events into existence. For example, if he says the word ‘explode’ then something will explode. This can happen even if he doesn't intend it to, which can lead to serious accidents. That's why he decided to start using rice ball ingredients in place of words.

While some people do understand him, his communication abilities are still dramatically inhibited. That's bound to cause some major social and psychological problems. 

Eri's quirk, Rewind, has enormous potential - she can “rewind” any living being to a previous state. This can eliminate injuries and illnesses, and even counteract aging. Despite its potential to be used for good, it can also do serious damage.

When Eri was a toddler, she couldn't fully control her quirk. She ended up accidentally activating it on her father, reversing his age to before the time he was born - essentially writing him out of existence. After that, her mother rejected her completely and left her in the care of her yakuza grandfather. Her grandfather's protege, Kai Chisaki, took a major interest in her powers because he believed they could be used to eliminate quirks from the human gene pool. To that end, he performs multiple painful experiments on her, which ultimately requires a full-scale rescue from a group of pro heroes. 

Hopefully, she'll be happier now that she's been essentially adopted by Aizawa and he's helping her to control her quirk. 

One of Lelouch's greatest weapons in his fight for Japanese independence is his Geass. Geasses are supernatural implants that can manifest differently depending on the user. Lelouch can use his to force any person to obey a single command. But once he issues the command - even if he does it unintentionally - there's no taking it back. 

This results in one of the worst moments in the entire series. When he explains his ability to his half-sister Euphemia, he uses an example. He says that if he were to tell her to open fire on the Japanese people waiting for her to make an announcement about the autonomous zone she fought for them to have, she would have to do it, no matter how much it went against her values. The Geass interprets this as a command, causing Euphemia to go on a blood-soaked rampage that ends in multiple fatalities, and her own demise. 

Because Lelouch can only issue one command per person, there's nothing he can do to stop her no matter how much he might want to.

Alluka, the only daughter of the Zoldyck clan, has an ability so fearsome that her family keeps her locked up to control it. Alluka doesn't use Nen herself - instead, she serves as the conduit for a creature named Nanika. Nanika initiates her ability by making a request. When a person fulfills three of her requests, she can grant them a wish. If the wish is small and easily granted, Nanika's next set of requests will be easily achieved. But if the person wishes for something complex, impactful, or impossible, the next set of requests might involve something like “give me your liver.”

Should the target of a set of requests be unable to fulfill any of them, they will pass away, and so will the person closest to them. If the previous wish was significant enough, the carnage extends to their entire network, wiping out their entire family and all of their friends. Left unchecked, this power could even end humankind. 

Not only does Alluka risk doing a ton of damage that she doesn't want to do, her powers also mean that her family treats her poorly - her brother Illumi even tries to assassinate her at one point. While it's not like the Zoldycks would treat her well anyway, she's still in a pretty bad spot.