After 15x02 I really couldn't resist. This is Amara (also known as, the Mark of Cain, or more commonly, the Darkness), and she is Chuck(God)'s sister.

*** SPOILERS FOR SUPERNATURAL SEASON 15, YOU HAVE BEEN WARNED ***

Chuck, not at full power after he is injured with a special weapon, appears at Amara's flat, looking for help. He wants her to open a rift to another dimension so he could leave the mess that he made. Amara won't let him leave, and is forcing him to live with his decisions and won't even let him leave her flat.

LOL.