Beat the rest of the game. Breathing technique, all the headless, some w/o confetti, the shinchini(spelling??) warriors, but he is all that is left.
All my instance does is walk around and block everything. I've parried 30+ times in a row and since he is on full health, he doesn't take parry-damage that I can do anything with.
IF I could get his health down sure, but he blocks everything. Just ****ing cheesy. At least if this was street-fighter or tekken, I could throw him.