In general, anime power-ups are a good thing. They are how fans know that character has become stronger over time and help to convey how hard work pays off. Many shonen anime even use the acquisition of new abilities to rescue heroes from the jaws of defeat.
However, there are instances where power comes at a price. Whether breaching cultural taboos or putting one’s own physical health at grave risk, these boosts of strength are incredibly controversial due to the dark stipulations behind them.
10/10 Nen Conditions Reduce One’s Ability To Fight
Hunter X Hunter
Nen conditions help to create the strongest characters in Hunter X Hunter while impeding their ability to fight in other ways. So far, Kurapika and Gon are the best examples of how making a pact can go wrong.
In Kurapika’s case, he can only use Emperor Time against members of the Phantom Troupe. Otherwise, it will be fatal to him. Gon’s decision to unleash his full potential against Neferpitou nearly got him killed and took a literal miracle to recover from.
9/10 Energy Steroids Destroy The User’s Body
One Piece
Like their real-life counterparts, One Piece‘s energy steroids have short-term benefits for long-term consequences. Although giving Hody Jones enough strength to defy post-time skip Luffy – which is no small feat for a villain without Haki or a Devil Fruit – it wreaked complete havoc on his body.
Despite being only 30 years old at the time, Hody’s body withered into that of an old man by the time King Neptune arrested him. His crew was not much better off, effectively putting an end to the New Fish-Man Pirates.
8/10 Ichigo Traded Spiritual Pressure For Physical Enhancement
Bleach
In Bleach, Ichigo needed a different approach to handling Aizen than those of the other shinigami. After training with his father, he learned how to concentrate spiritual pressure into raw physical strength so that he’d have a counter to the villain and his Hogyoku.
However, this was a wildly controversial technique that risked him never becoming a shinigami again. Nonetheless, he realized that if Aizen wasn’t stopped soon, there might not be a Soul Society left for him to save. Ichigo wouldn’t have been able to live with himself if his friends got hurt.
7/10 Titan Shifting Has Drastic Consequences
Attack On Titan
Shifting is easily the most iconic ability in Attack On Titan. It transforms the user into one of the Nine and grants them a uniquely devastating power. This also makes them desirable to nations across the world, as Marley’s military used their Warriors in order to invade and oppress others.
However, shifting also has dire consequences. In addition to being treated with fear and mistrust, the user must transform into a pure titan themselves before claiming new power. Additionally, they are destined to die thirteen years after doing so.
6/10 Vampirism Denies One Their Humanity
Hellsing
Since the beginning of Hellsing, Seras Victoria has refused to embrace vampirism. Her unwillingness to drink blood made her significantly weaker than other vampires, which was problematic during the Millennium Organization’s attack on London.
Eventually, Seras caved and drank the blood of her fallen friend in order to become stronger. However, this damaged her connection with her own humanity, and the innocent young girl was no more. Seras may still not be as sadistic as Alucard, but she’s no longer recognizable as the person she once was.
5/10 The Holy Knights Thought Demon Blood Made Them Stronger
Seven Deadly Sins
The Holy Knights of Seven Deadly Sins had an ironic name. Misguided by the corrupt Fraudrin, they turned against the heroes and repeatedly tried to kill them. When conventional strength failed, they consumed demon blood in hopes of increasing their potential.
Predictably, this was a horrible idea. The blood killed lucky knights immediately. Those who survived were transformed into lumbering monstrosities and turned against the people of Liones. While eventually defeated and restored, the traumatizing experience tarnished their reputation and home.
4/10 The Stand Arrow Was Dangerous By Design
JoJo’s Bizarre Adventure
Although the single most valuable item in JoJo’s Bizarre Adventure, the Stand arrow was associated with tremendous risk. While capable of giving its user a Stand, it mostly just killed its targets. Those with low amounts of willpower were particularly prone to death, which should give a reasonable person pause before using it.
However, the Stand arrow can also strengthen characters who already have abilities, turning their Stand into a “Requiem.” Between Giorno and Yoshikage Kira, these ultimate forms are nearly unbeatable and suit their host’s needs perfectly.
3/10 Overhaul Created Quirk-Enhancing Drugs
My Hero Academia
Using Eri as an experiment, My Hero Academia‘s Overhaul created two separate Quirk bullets. The first destroyed its target’s special ability, effectively neutralizing them in battle. Although less discussed, his second bullet was much more interesting.
It drastically increased one’s ability to use their Quirk, making them much stronger than they have any right to be. For example, a villain previously only able to make blades from his elbows could now unleash a torrent of razor-sharp steel directly from his chest. It took Kirishima’s ultimate hardening to survive.
2/10 Anyone Could Bond With Vaatu
Legend Of Korra
In Legend Of Korra, it might seem unfair that only one person could be born as the Avatar. This gave its titular protagonist a significant advantage against the villains, even defeating those with more prep time and strategizing like Amon and Zaheer.
However, by binding with the dark spirit Vaatu, Unalaq effectively transformed himself into an evil avatar on Korra’s level. Single-handedly possessing the strength to destroy Republic City, it took the essence of Korra’s soul itself in order to stop him.
1/10 The Reaper Death Seal Kills Its User
Naruto
The Reaper Death Seal is the most iconic forbidden jutsu in Naruto. The user summons a shinigami to extract their target’s soul, damning themselves to an eternity of suffering in the process.
When Orochimaru pushed Hiruzen to the cusp of defeat, he used it to neutralize Hashirama and Tobirama. While failing to kill the sannin himself, Hiruzen destroyed his arms, crushing his ability to continue his campaign against the Leaf. It took Orochimaru many years before he returned to his former glory, and by then, many other powerful shinobi could easily stop him.