User blog comment:Rafe Adler/"Stuck in the Middle (With You)" Discussion/@comment-1031724-20170217183659/@comment-1031724-20170217195456

I wonder about Knights of Hell. Wouldn't Princes of Hell be higher? And the Colt did kill one of the Princes, Azazel. They did have to go through all the trouble for the First Blade and Mark of Cain to kill Abaddon, but the Colt had vanished then, and now we know where.

One thing's for absolute certain - if the Colt does come into play it won't be used to kill Lucifer. Dean already tried that, he's one of the five beings immune to it. (Well, not entirely immune, but it can't kill him)