There are many unhinged antagonists in anime. The unhinged don’t tend to have many patterns, especially not in anime; they may be normal one minute and wholly deranged-looking the next.
Typically, an unhinged villain will lack any moral constraints or be sadistic and cruel enough to carry out all manner of horrid actions without remorse.
Disclaimer: This article contains discussions and descriptions of violence and the subject of deteriorating mental health. Viewer discretion is advised. Furthermore, the article might include spoilers for all the shows mentioned.
Ken and 10 other unhinged anime antagonists
Ken Ichijouji of Digimon Adventure 2 started as an ordinary kid alongside his brother Sam. A Digivice and the tragedy of losing his brother transformed him into a cruel and cold Digimon Emperor.
Ken is best compared to other characters that underwent mind control, like Vegeta in the Majin Buu Saga. The Dark Spores and Dark Ocean made him more sadistic and cruel. It caused him to abandon humanity for the digital world until multiple encounters with the new DigiDestined changed his outlook.
After several months in a coma, he returned home after finally regaining his sanity after his primary Digimon, Leafmon, forgives him for his abusive actions.
He doesn’t join the DigiDestined at first, trying to do things on his own, but they helped him before he could sacrifice himself. It turns out that the power of friendship is pretty awesome at helping people.
General James Ironwood of RWBY may have started as a somewhat good guy in his Volume 2 introduction, but by Volume 8, he’s unhinged, PTSD-ridden, authoritarian. To summarize: Ironwood is the head of the mighty Atlas military, going off because of his belief that he is the hero in this story.
With the world turning against Atlas after the mostly mechanical army got hacked, he decided that the solution was to close Atlas’ borders. Ironwood became more unhinged as tensions rose. It culminated in placing an arrest warrant on Team RWBY for disagreeing with his insane plan to abandon Remnant and float away.
He shot Oscar Pine (a literal child), shot one of the councilors (dead), tried to kill Winter Schnee and the rest of the heroes, and generally went down that slope as soon as he felt he couldn’t win. Because in his mind, he’s the hero. Nobody else. He died thinking that, dooming people because of it.
8) Teru Mikami
This man was already unhinged from minute one. A criminal prosecutor chosen as the Hand of Kira by Light, Teru Mikami of Death Note, already considered Kira a God. The problem is, he’s a lot more twisted than Light is, having a black and white view on justice as punishment.
Those that don’t contribute, the “lazy people,” as he called them, likewise with criminal records, are fair game for death. His mental deterioration escalated as he was tricked into getting a fake notebook.
He had already caused chaos by writing down the names of many people, saying “Delete. Delete. Delete.” like some Cyberman or Dalek from Doctor Who. Mikami kills himself with a ballpoint pen in the final episode and creates a diversion for the SPK and the task Force.
7) Himiko Toga
Himiko Toga of My Hero Academia has a blood-draining quirk, and she can transform into a physical copy of someone whose blood she drinks. She was bloody enough, going on a series of gruesome murders ever since middle school.
All this earned her the attention of the League of Villains, and she hasn’t stopped ever since. She’s a knife user “in love” with Deku and Ochao and recently made a bloody mess of an “interview” by a rival syndicate after losing Twice. Her fate is a mystery, but chances are it’ll involve blood.
6) Makoto Shishio
Cold, sadistic, and mentally disarranged, Makoto Shishio of Rurouni Kenshin fame is an opportunistic sociopath and doesn’t hesitate to slaughter to get his way.
Following betrayal by his comrades that left him severely burned, he was forced to wear bandages, giving him a mummy-like appearance because the burns completely removed his sweat glands. He could spontaneously combust if he fought for too long.
Shishio was a social Darwinist and believed the Meiji government was too weak to govern effectively. So Shishio planned to hijack a battleship and attack Tokyo.
Kenshin stopped him, and the two dueled to death where Shishio used his lover Yumi as a shield to block Kenshin’s final blow and stabbed her through. Ultimately, he lost as his body ignited and he burned to death.
Doppio is the other half of Jojo’s Bizarre Adventure: Golden Wind’s unhinged main antagonist Diavolo. Unlike Dio or Kira, Diavolo’s neither a world conqueror type nor a serial killer. He wants to continue to be a mob boss, albeit anonymously. To that end, he eliminated anyone who knew him, including attempting it on his daughter Trish.
As Golden Wind progresses, he gets further and further deranged. He started making huge mistakes like moving too quickly when Giorno’s gang was body swapped. His final act was to try to kill Giorno after he supercharged his Stand.
For all the lives he took, Diavolo was sentenced to an infinite loop of death. He’ll never be truly able to die, a fitting end for a villain whose Stand allows him to skip time.
4) Tyrian Callows
Tyrian Callows of RWBY, an unhinged serial killer before he was picked up by main villain Salem, Tyrian is arguably the most devoted to the apocalyptic plans of his “goddess” Salem. Tyrian Callows first arrived on the scene in Volume 4 and made a big splash by kicking team RNJR around and poisoning Qrow.
After having his tail replaced by a metal one after Ruby Rose sliced his flesh one-off, he and Watts wreaked havoc in Atlas. Hacking elections, slaughtering innocent rallies, framing Ironwood? Good times! Tyrian was captured, but not for long as the situation between Ironwood and Team RWBY deteriorated.
Taking advantage of the chaos, Tyrian would slay Atlas Ace Operative Clover Ebi and vanish back to Salem’s welcoming arms with malicious glee. Time will tell whether or not this unhinged scorpion’s poison will come back to bite him.
3) Kid Buu
When Maijin Buu eradicated the Supreme Kais in Dragon Ball Z, the unhinged Kid Buu performed the deed. Kid Buu is unpredictable, void of restraint, and has no sanity. He barely speaks, and if he does, it’s a childish voice with hysterical laughter.
He blew up the Earth as his first action and pursued Goku and Vegeta to Kai’s world. His vicious and sadistic behavior was not satiated with just fighting Goku; he did likewise to Vegeta and Good Buu before finally being obliterated via Super Spirit Bomb.
2) Nui Harime
Nui Harime of Kill la Kill was born by Ragyo Kiriyuin in an artificial life fiber womb after six months. Nui is not human but is very unhinged. If her breaking of the fourth wall via leaning on the titles, reaching through camera angles to stroke Satsuki’s hair, and disrupting the credits doesn’t scare you, this will.
Ryuko Matoi’s whole motive was that Satuski supposedly killed her father or ordered the hit. Ragyo ordered the hit and Nui carried it out. Nui Harime seemed invincible, unable to be harmed by multiple explosives or touched by Ryuko or Satsuki.
That is, until the time skip in which she loses her arms. Permanently too, because of the twin scissor blades being combined. She freaked out, yelling that she hated them all and could barely escape.
What’s really scary is her appearance and voice, like a cute little girl with a deadly weapon. She would later become one with the life fibers to supercharge Ragyo.
Dio from Jojo’s Bizarre Adventure makes it to the top of the list of unhinged characters. He starts with a bad home life and then tries to screw over his new home life. He molests Johnathan Joestar’s girlfriend, kills his dog, and attempts to poison his father, all while being smug and narcissistic.
That was before the stone mask morphed him into a vampire. Afterward, he went on a rampage through England and managed to turn Jack the Ripper into a vampire. He killed Johnathan and then, well over 100 years later, managed to get a Stand that stops time.
His bordering insanity doesn’t get any better after gaining more Joestar blood, ranting, and shoving a road roller at Jotaro Kujo.
Note: The article reflects the writer's own views.