User blog comment:DCrangers/Crowley vs Castiel Death battle/@comment-3481504-20130709012413

Without that "at the start of Season Eight" parameter, as a Seraph, Castiel would win. As, Seraphs can beat any Power of Hell. He would, as he puts it, "bury [you]" to the grip of Death. But, even in the beginning part of Season Eight, Castiel would eventually beat Crowley.