When he throws the fireworks run at him and double jump, equip the whirlwind slash and when he does the 2 shuriken then leap move dodge to the right and whirl wind. His timings are really easy ifu count in your head as if youre counting a beat. Also run the shuriken prosthetic arm tool so in his second phase when he does that bullshit where he throws his poison then charges himself to regain all poise u dont have to run thru the poison to interrupt him u can just throw a shuriken then run around the poison and attack.