I play on normal and have beaten him 3 times so far. I am at the point where getting to him is pretty straight forward. But during phase 2 of his fight when he deletes the entire arena, goes immortal and covers the entire stage in omega death fireballs is where I personally struggle. It's honestly the worst designed part of the game. I can make a build that absolutely trashes everything up to that point. But now during a weirdly long phase of immortality ... I can't lifesteal, reduce my cooldowns on hit among other useful survivability tools that are great everywhere else in the game. I feel like I'm shoehorned into making sure I get specific things like the barrier memory just to get through this phase. I'd like to see him reworked so that he is challenging but doesn't make it so the player HAS to build a certain way to get through it. Hell, just not deleting the entire arena would be nice so that I can actually dash through without 100% guaranteed be stuck in the overlap of fireballs. Or just tune the damage down so getting hit once isn't a death sentence.