I dunno, Cleric Beast (10-15 tries) gave me more trouble than anything in Dark Souls 1. But I didn't beat the game, only got halfway through. Only played 10 hours of Dark Souls 2
Father G and BSB were both pretty easy for me though, I did Father G in 3 tries and BSB in 1.
We must be opposites or something. Did Cleric Beast on first try Father G and BSB both took me a few. Think I need to work on gun/parry skills. Relying on the shield in the souls games is hurting my bloodborne skills but I really like the change in pace to it.
Bloodborne might be my favorite of the games so far.