User blog comment:Kajune/Does Dean require demon blood for Michael to possess him?/@comment-27593090-20151230201510/@comment-27593090-20151230215026

@darchangel 66

yes AND his vessel was going to resolve (look at the pictures the vessel started to resolve) he needed the blood to slow it down

@seraphlucifer

Yes. if lucifer possesses sam he doesn't need the blood because sam is his true vessel.