After Sam gets rid of Dean's mark, the Darkness is released. Also known as Amara, the Darkness is found out to be God's sister (even I have to admit that plot twist was not within my range of stuff to expect from the show). Played by Emily Swallow, the character is perfect for being a cold being who somehow manages to get our sympathies for being locked away by her own brother. As it turns out she grows by devouring souls whole and doesn't even die after being struck by the holy power of the angels. She's out for vengeance while also having a strange attraction to Dean, the other bearer of the Mark of Cane.
As everyone was saying before the release, Lucifer is indeed back. Sam goes to hell in episode 9 with the help of Crowley and his mother. But another plot twist...when Dean and Castiel get down there to help him out, Lucifer jumps into Castiel's body without them noticing. Now in episode 11 he's out and at full power (or at least close to it since he can't be stopped). Of course that is so unlike Misha Collins' lighthearted and lovable Castiel nature.
So we have God's sister and the Devil running loose on Earth too. Just makes you wonder when is God himself making an appearance? Be sure to comment and tell me your thoughts.
...and a definite TV show to watch normally or even binge watch...