It should scare him, but it doesn't, because nothing does anymore. Not demons, not Hell, not the very real possibility - the probability that he's looking at something that might be himself. He watches Castiel, Sam, watches the rise and fall of the thing under Dean's skin, feels Neil close and draws strength from the closeness. Watches all of them, waits to see if he's needed. Aware that being here to witness this is a thing in itself.

All of them standing together. They haven't abandoned Dean, would never abandon him. This thing needs to know it. Will know it.

Will know that it had already lost the instant it invaded.