After a while of traveling alone, hunter!Cas shows up at the bunker wearing military fatigues, Aviators, and a fucking thigh holster, and toting a Predator crossbow.
Dean gives Sam the keys to the Impala and croaks, just drive. Anywhere. For a long time.

OH MY GOD LOOK I FOUND THIS AMAZING ART ON deandraws devianart (same username) ITS SO AWESOME I love it