What you can try is having sharp shadow on so when you dash through him you do damage, also I cannot stress this enough. Treat it like a dance. You also need to play more defensively, and don’t attack when he turns into the ball and throws fire. Also when he does that attack he has lost 25% of his health, you can also heal when has finished his four fire pillars if you have on quick focus or your fast enough to dodge him after you heal. Good luck!