User blog comment:Kajune/Lucifer, first son?/@comment-109.193.194.114-20160413105639

Michael might be dead anyway. Amara mentioned that she was looking for Lucifer. She knew that he was recently in the cage as Crowley mentioned that he helped to put Lucifer (Our little World) back into the cage. She might have simply killed Michael as she took a look in the cage. On the other hand, if he is still alive, maybe she doesn't care about Michael at all.