When it comes to protagonist that kill you usually get two mindsets. The overly forgiving type, that refuses to take a life, and thinks knocking someone unconscious will stop them from ever committing a crime again. Usually this person is also a hypocrite, who while sparing genuinely evil people, like rapists, and slavers, gives no qualm when killing monsters or demons, who are just minding their own business. The overly ruthless type, that kills someone just for bad mouthing them, and will even go out and kill their friends and family to boot. They even try to paint themselves as someone who is reluctant to kill, or someone who only kills when they have to. But often enough they deliberately exasperate their victim, choosing to kill when they could have just walked away. What have been some series where this is NOT the case. Stories where when the protagonist spares someone you think "yeah, that guy learned his lesson" and when they kill someone you think "fucking bastard, he deserved it."