Champ Axemaster Gwyllion
I experienced the same thing, although a group of about 10 people were able to kill him. Unlike most of the enemies I’ve seen during the beta, we were actually able to drain his break bar and interrupt the kill move. It was pretty satisfying, so I don’t mind his special move.
However, I do propose they rename the “tracking” to “hacking.” He’s an axemaster…and that damage is unreal. :P