A/N: Based on a prompt from tumblr by whump-galaxy:
"Magnificent wings. They'd look perfect on my wall."
Ketch circled Castiel, angel blade drawing along his bare skin, making his gut tighten with fear. Somehow he'd gotten the better of Castiel, some British Men of Letters magic or technology, and now Castiel was chained up in a dungeon. And of all, things, his wings were showing through into this dimension. He bristled as Ketch ran his free hand through his soft, tawny feathers. The angel blade was right against the shoulder joint, pressing hard, nearly slicing. Cas tried pulling away, but the chains held fast.
"Magnificent wings," Ketch breathed out, voice deep, excitement in his veins. "They'd look perfect on my wall."
Cas screeched, and tried kicking out at him. His aim was poor.
Ketch slashed.
Castiel screamed, and his wings continued to be cut into, blood dripping to the floor. Ketch hummed to himself, seemingly at peace. And maybe he was. After all, Castiel's wings were going to end up on his wall.