Castiel: I told you, war is coming. War. And I did what soldiers do. Now we needed the spell to open the rift, and I got it. We need four major ingredients... the grace of an archangel... a fruit from the Tree of Life... the Seal of Solomon... and the blood of “a most holy man.” We find those things, we can bring everybody home. And together, we can beat Lucifer and Michael. This is the only way we win, and this is the only way we survive. It's like you said, Dean. Whatever it takes.