This is just a thought of mine.. what if.. savathûn was on the pyramid ship instead of xivu urath? (Probs didn’t spell that right but oh well). Because if you think about it savathûn possessed Osiris the moment sagira was killed so how do we know it was Osiris telling us it was xivu urath and not savathûn just framing her sister and she comes to us to help her do her dirty work.. What if xivu urath was sent by the darkness to stop savathûn from communion with the darkness from the pyramid ship. Maybe savathûn lured Osiris into the pyramid ship to trap him and possess him by killing his ghost and his light making him vulnerable. Udren sov was the same. Lightless. Vulnerable. Just like Osiris was.