I think he is just a bit luck based depending on how agressive his minions are to you.
When multiple of them attack you at once it can be really hard to dodge them. And when you get hit once chances are another one attacks immediatly after.
And some of them are off-screen almost everytime because you can't really monitor them all at once, while attacking R.om
Yeah, honestly the fight is broken, imo. Either his minions are super aggressive when you get close or he spams all of his abilities in such a manner that you can never get an attack in in the third phase. The only time I beat him is when his minions ignore me and he doesn't spam abilities. Most of the times I die it feels like there was absolutely nothing I could have done to avoid it (sprinting full speed and getting hit by 3 meteors comes to mind). Makes it feel like half of it is luck and that really takes away a lot of the satisfaction for defeating a boss. Would rather feel like I won because I controlled the fight well and not because I got lucky.