Angel Of The Stars

AU where dead humans can be reincarnated as dead angels. "I used to be human. The man on Hell's side killed me when they asked for my father's journal. He was like you. He was a hunter." "I have always loved the stars, Castiel. The one before me created them, and I care for them. I used to talk about them all the time to you, remember? Because you were my friend. My only friend."