The Hammered achievement for Divinity Original Sin 2 which you achieve by defeating an endgame boss in your first encounter with them in act 1. I used a very cheesy method where I chain teleported the boss and her minions on to a rock in the middle of the sea. And then my archer who was on a cliff type thing on the other side of the beach slowly shot them to death. It was very funny!
@Melkath very helpul and important questions to ask urself, yes