Killing in anger- inability to control emotions in a healthy way. 

Killing on orders- I’m merely a tool and do as I am told. Also I assume you mean in a army standpoint. That is a kill or be killed scenario, not mowing down a room of unarmed civilians. 


Natural is also a shit word, companies like to say food is “all natural” yet so are some poisons! Same goes for your use. Natural would likely mean killing for the sake of survival (like other animals) and neither option you presented directly leads to that but if I’d have to say I’d go with killing on orders if I were to stretch it.