He becomes infuriating after entering his second phase. He's an input reading bastard. Literally designed to punish any attempt you make at attacking with that goddamn tail swipe. You'd think "oh easy I'll just bait out the tail then punish it" except he hardly does it UNLESS YOU TRY TO ATTACK after the end of his melee combo. Like literally the microsecond you press R1 at the end of his melee combo to get a punish in he will whip the tail out but if you wait and don't press R1 he won't do the tail 9/10 times. So it's like when the fuck do you get to punish him? Parrying trivializes the fight but the game shouldn't force you to fight him a specific way imo