User blog comment:KillRoy231/How will the season end?/@comment-1031724-20180103205910/@comment-1031724-20180105220856

Angel blades could penetrate his vessel but not really do anything to him. The only other weapons that seemed to affect him were Hands of God which can kill just about anything other than Amara (he only survived coz he wasn't hit with its power directly), and the Colt, which did hurt him but didn't kill him coz he's one of five beings it can't kill.

Princes of Hell of course aren't one of the five, as we saw with Azazel, but the Colt's gone now.