ok hear me out. what if they'd gone down the jimmy path, but that's not where it ends. the ending is them gathering all of their friends and family (something that is now possible to do because heaven is just one huge stretch of people, not dissected by doors and hallways) once they realize cas is still in the empty, because of course that means they're going to storm the empty and get him back. they have to — it's cas. plus, no one dares disagree with dean winchester when he's got his gameface on, and this is about saving his angel from eternal nothingness and getting him back home, so there's really, really no two ways about it.
so everyone, including hunters and other unlikely allies — even angels, maybe, who fought by cas's side at a time and have regretted not fighting for him before — everyone comes together in the real, final battle against the empty. that is how important cas is to this world, and how it all is fated to end.
but just before the fight's actually kicked off, there's a scared, young voice. a minor angel speaking up.
"what if killing the empty releases all of the angels and demons in it?"
(and because time works differently in heaven, and sam can't miss thee fight for his best friend and brother, so he's there too) sam just turns to share a familiar look with his brother.
dean smirks back.
"well," they cock their guns in classic winchester sync. "then we'll have work to do."
