Definitely 6p pain. Shisui is now easily counterable with irrem standard block debuffs. Pain can do 4 mysteries in 1st round that can nuke enemies easily + even if you beat him he revives and spam shinra tensei multiple times. Also he still doesn't have BT so once he gets it he will be even more OP. I would say even ashura full BT is now much more annoying than shisui.