The killer could also have pulled Asmodean's body into TAR (not sure if Slayer can do that, and it doesn't fit his M.O. anyway, but plenty of others). That would certainly leave no body behind--not in the real world, anyway. I'm not saying I believe that's what happened (I'm just going to wait for the perp to reveal himself/herself), but it's a possibility that shows that Balefire isn't necessarily what happened.