The Ferrymen are, in my eyes, fine, but their fast speed, decently high HP pool and their placement next to multiple tough enemies like Swordsmachine (my beloved) whenever they appear make them very annoying.
I hate the Mindflayers. They're so damn annoying and there's nothing you can really do except parry their blue homing orbs. They are the things that kill me the most. The other things is my own incompetence and the Ferryman with 2 Swordsmachines in the second to last room.
I think I died maybe once to the Weezer room. On my first ever attempt at P-2.
I attempted P-2 half an hour ago, and I didn't die on Sisyphus at all, which surprised me. I didn't even die to the infamous Weezer room. The other parts did get me, though. I died 17 times. I think I died once or twice to the Panopticon, but Sisyphus was extremely easy compared to the other rooms.