sinners and saints
The back story is that boyking!Sam and demon!Dean are the only survivors from the war between heaven and hell. Boyking!Sam revives lives wherever he goes. Demon!Dean kills supernatural creatures in the way.
Thank you so much sammycolt24 for providing the idea of the battle and the knife of Cain.
This is a weird image even for me. I hope you are not freaked out by it...