I mean his character is very arrogant. He probably believes that it’s beneath him to do the hard work of killing them, so he gets the player character to do it instead, safe in the belief that he can best them when the moment comes. He’s presumably the leader of the Roundtable Hold for a reason, which is to say he’s capable in combat as well as seeking knowledge. He evidently thinks he’s got what it takes to take care of some up-and-coming Tarnished. He’s very wrong.

Is out of estus, still tries to drink. All knowing my ass

He doesn’t just let us kill them all, he keeps tabs on us and gathers intel from all of them, including their spells and techniques, which he plans to use to kill us. And, truth be told, combining all of the powers and skills of the strongest beings in the world together is a pretty solid plan.

I doubt he planned to kill the player. He was planning to wait at the finish line to beat us to it. Then he realizes who the final boss is, becomes coinvinced he can’t beat it, and reasons that since it is impossible for him it must also be impossible for everyone else. Then he tries to kill us because he is afraid we will prove that it isn’t actually impossible. That’s my read on it, anyway.

What game is this?