A
SUPERWHO – After the takeover in New York, Sam and Dean follow a trail of missing persons and hunt down the sole surviving Weeping Angel. However, a skeptic Castiel tells them it is impossible to contain one, and that at some point it will escape. He later reveals the true origins of the creatures: they are the spirits of fallen angels who were consumed by human emotions such as rage, jealousy or vengence.
Oh dear heaven I think this is the best one yet.