the archetype you’re looking for is “Anti-hero”. a kind of hero with grey morals and questionable ethics - but whose actions still have a mostly positive result

typically - a hero will try to rehabilitate a criminal first, throw them in prison second, and only kill if they’ve exhausted all other options. killing is usually shown as something that the hero struggles with greatly

an anti-hero will often skip the “when will murder be my only option?” ethical dilemma regular heroes have and go straight to the killing. in their stories casual killing is either shown as normal, or serves as a plot point that’ll come back to haunt them later (“i killed that man without thinking, but now he turned out to be innocent”)

this is not the only difference between the two of course, but i don’t want to type an essay