you and Genya were fighting then Genya ate something that was apart of the demon. And he was in his demon form.. You didn't know he could do that and you thought you would have to fight him and the demon.. But he instead attacked the demon and ended up slicing the demon you and him were attacking and he was covered in the demons blood as he was breathing heavily and drooling.. He was fighting the urge of his demon form to eat humans..