You want it darker? (слэш)

Don't let the title fool you, this is a fix-it.
(Epilogue to Crossing Lines, but can be read on its own)
***
There is a ring on Cas’ finger with a shining white surface, and he is holding a tall black scythe.
“Cas?” Dean says again, with more fear this time. He can’t. He can’t do this. He can’t.
Chuck is staring at Cas too. They all are. Chuck’s eyes actually pop, nearly bulging, the surprise in his face tinged with something like rage.
“You!” he snaps. “You’re not even in this story, your part is long over. Why aren’t you dead? This isn’t even about you, it never was! Why, in my own damn name, aren’t you dead?”
Cas takes two steps forward.
“Good question,” he says, his voice all gravel, and swings Death’s scythe down in one long arc, lopping off Chuck’s head.