Mary fell into the void with Lucifer in much the same way Sam did in the season 5 finale. Cas died by Lucifer's hand in that ep too... God brought him back last time. Seems fitting if Lucifer's son brings him back this time around... Maybe?
Yeah, that’s what I’m thinking…
Sam’s upstairs with the nephilim literally cornered. Kelly got zapped to nowhere in a blaze of light when it was born, and it scorched the floor as it walked to its room.
I guess I should call it he? Jack?
But right now he’s literally cornered with Sam standing over him.
Meanwhile Dean’s outside kneeling over Cas, My guess is that in his panic, the nephilim’s gonna reach out to the closest thing that’s pledged its “faith” to him, and that thing is Cas.
(oh gosh this bit might hurt worse than the actual finale did)
Cas suddenly takes in a huge gasp of air and opens his eyes, and Dean reaches out to him and there’s this shocked hope and suddenly Dean’s all about helping Cas sit up and then get to his feet. But Cas just blinks at him, maybe acknowledges Dean’s existence… and then walks purposefully toward the house without any other explanation…
Dean follows, trying to get Cas to talk to him, but he’s single-minded. Cas pushes past Sam and helps Jack to his feet. Maybe he even thanks Sam and Dean for their help bringing Jack safely into the world, and then *poof* they’re gone…
(because Cas isn’t himself still. ESPECIALLY if it’s his connection to the nephilim that brings him back.)