Leroy Schwartz

The protagonist of the manga Leroy has superhuman speed strength and stamina. He is accompanied by his sentient sword Ragnarok. He is quickthinking though sometimes he can be irrational. He despises those who kill for no motive other than profit. He keeps sealed within him an immense power along with feelings of isolation from other humans because he is a Lycanthrope. The power within him only manifests itself forcefully whenever Leroy sustains critical damage. Source: Wikipedia