Tiers of "heroes don't kill people, but we still want the villain to die because something something justice" in ascending order of "well, technically":
Hero simply leaves; villain coincidentally killed shortly thereafter by something unrelated. Example: murdered by treacherous minions.
Villain accidentally kills self while attempting to harm hero. Example: shoots at hero, misses, struck by improbable ricochet.
Hero and villain's conflict leads to perilous locale from which only hero escapes. Example: fighting on train tracks, villain hit by train.
Villain defeated non-lethally; dies anyway due to unpredictable or outside factors. Example: villain disarmed, dies of magic curse.
Hero employs lethal force, but that isn't what kills villain. Example: villain evades hero's attack and falls off cliff.
Hero deliberately employs environmental hazard to kill villain. Example: hero throws villain into live electrical wires.
Hero apparently kills villain; later developments reveal villain survived and was killed by something else. Example: hero kicks villain off cliff; post-credits bonus scene shows them getting up and walking away, then getting eaten by a bear.


















