Jin
Kariya

Jin Kariya is the leader of the Bount, the antagonist of the anime's first original arc, and a man with a legitimate complaint and no proportion whatsoever. The Bount were an accident: a failed Soul Society experiment produced humans who do not age and who sustain themselves by consuming souls, and Soul Society's response to the mistake was to hunt them.

Kariya's answer is to destroy the Seireitei. He gathers what remains of his people, breaks into Soul Society, and works toward collapsing the Soul Society and the Human World together, and he is charming and reasonable about it right up until he is not. He consumes living human souls, which even most Bount will not do, and he enjoys it visibly.

He fights with Messer, a Doll he merged into his own body, giving him wind at close range and regeneration that outpaces most of what is thrown at him. Ichigo Kurosaki cannot finish him with Shikai. What eventually beats him is Uryū Ishida relearning how to use the Quincy Bangle without burning himself out, and then Ichigo, and Kariya dies having been right about what was done to his people and wrong about everything he did afterwards.