In the first third of the fight all you have to do is you your telekinese to hit him of balance and then select jump and target him then press b. In the second third of the fight all you SHOULD DO is block until your rage bar is at full the attack him with IMMOLATE. Continue that proces until cinamatic. In the last third all you have to is attack him with fury and berserk. Attacking him with Immolate wont work any more. Once you kill him the game is over.