Reread Jigokuraku with the anime coming out. Gantetsusai remains my favorite character in-series, mainly because I like his character's take on the whole "berserker who loves to fight trope."
Unlike most characters embodying the trope he doesn't stay as a milquetoast idiot who only cares about fighting or gets his attitude validated by a huge number of power-ups or dies valiantly and happy against a stronger foe.
But realizes life is precious and being a general menace to society is a waste of life and becomes a healer.