Locked: Cas & Balthazar
Cas, darling. I left because of you! You're the one who proved we could do it! You know, you're whole freewill campaign. Fighting destiny! You wanted to show us we could do anything, so I'm doing just that.
Besides, you were busy off following that human, and trying to keep him safe. So I took matters into my own hands, did what I thought was right.