All I know is that I havent seen latbag since I ..uh...Cut His Friggin' Head Off! Ha Ha! That was my 3rd encounter with him. He certainly remembered me killing him, though!Maybe in the second half when you get all the powers, But the re-spawning captains are a hassle.
http://kotaku.com/nobody-knows-how-to-permanently-kill-shadow-of-mordors-1644777204