Okay, but there's a lot of ways to make someone a legendary fighter without making them some bloodthirsty killer or someone who went crazy because someone died.
So, imagine there's a swordsman who only ever picked up the sword to protect people. He doesn't like fighting, and refuses to if he can, but he's a master fighter and disables people without ever drawing his sword -- you know, punches, kicks, the scabbard, etc. The only time he would ever draw his sword would be for his ult, and it's only usable as a last resort, like maybe if a teammate is low health around him.
Or imagine like an Asian monk, who is an absurdly good fighter, but doesn't fight.
Or an inventor, who always created things to help humanity, but was forced to create devices / a suit / something to fight with to protect his city or something.
Or a priest of some sort, focused on healing and buffs rather than killing.