Well, this is a cheap tactic just to make him not able to attack at all. Which is incredibly cheap. All you actually have to do is get into the right position and spam so you don't dodge the wrong way and miss an attack and he kills you. That and surviving his killing spree when he has jumped from hanging on the edge. If you want to play him fair it is instant rape. You can just hit once or twice before he starts a melee and if you go a few steps back he uses his tentacles who is so damn hard to predict, dodge and survive.