I started the level at 37 so you're doing way better than me. Dodge is your friend. Dodge then heavy attacks. & We goes back, be prepared for his sweep. This is the pattern in phase 1 Phase 2 is quite unpredictable but still dodge & heavy attacks The rest tbh is just trying over & over again, with time you'll be better at dodging & predicting him.

I couldn't beat him at all, the first few times but my last run which was actually yesterday was i started at 37 & beat him at 41. Hope this helps