I think they should add assassins that try to kill you if you do something bad. Like if your kill the apex leader in a village then it should send assassins after you. It will alert you with there is one by. Or like the shadow of Mordor where if you attack something but fail then the mob would keep a grudge on you
That's a neat idea. Also what if you kill all the NPCs the NPCs should start throwing tomatoes at you. Or start yelling BOO!!