While it's a whole different story in NG+ cycles, with the right approach, this boss can become pretty easy in NG. Slap great magic shield into yourself to block his fast weak attacks with no problem to your stability or stamina and negate the bleed buildup completely. Carry a big stick (fully upgraded great clave) and give a single slap on him after big openings, don't get greedy. When you see he entering in stance and a black aura in his katana .... that is his grab attack, that is unblockable, do massive damage and will buff his attack and defense after. Roll toward his left foot (your right lower side when locked on) . After he is down to <30% of life, he will stagger, giving you some free hits. After this point, he will do the grab attack more constantly and do a new jump attack that needs to be dodged by rolling away.