Season after season we have traveled this winding, crazy, path. Never knowing from one cliff hanger to the next how this would all end. When would this end. After 15 long seasons we have the answer. In just a couple short (because fans are not ready) weeks this adventure will be over. There is hope that some how the show will be resurrected. Or there will be some type of spin off. Reality is, we never know what the future holds.
In the eleventh season, the Darkness takes a human form and allies with Dean briefly. As the brothers fight a new kind of evil human brought on by her release. Which involves a baby that becomes the bearer of the Mark of Cain (the aforementioned weapon).
The baby quickly ages into Amara, the new embodiment of the Darkness. They go through the steps to collect a powerful light. Which is powered by souls that can destroy her. This includes allying with Metatron. Amara attacks God after revealing he is her brother. Who happen to imprison her. They then reconcile with Dean and grant him his mother resurrection.
The season concludes with Sam being shot by a newly appeared unknown British woman.
Season 12 kicks off with Sam being kidnapped by ‘British Men of Letters’ member, Toni Bevell. The unnamed woman from the previous season finale. Dean struggles with the resurrection of his mother Mary. Castiel and Crowley must ally to search for the body-jumping Lucifer.
As Lucifer continues to possess more powerful people to get what he wants. Including the President of the United States. Things become more complicated. While trying to stop him, the Winchester brothers are arrested by the secret service. Mary and Castiel must turn to the Men of Letters to find them.
The brothers make a deal to escape that costs them the life of one of their own. They discover that Lucifer has a child and the child’s mother tries to convince the brothers that he is good.
The thirteenth season hosts another return of Lucifer. Along with the news that his child named Jack, is now a teenager and fully thriving. The brothers argue over whether to kill the child, and Jack himself deals with his own identity crisis. The brothers must fight threats from both sides to keep them from stealing Jack’s powers. While also dealing with a creature of extraordinary powers.
Lucifer ends up being the ruler of Heaven, and reunites with his son Jack. Michael possesses Dean for a battle with Lucifer. After winning he betrays the brothers and leaves, taking Dean’s body with him.
The fourteenth season
starts in the aftermath of Michael’s possession of Dean. Sam, Castiel, and Jack must stop Michael’s plan to bring demise into the world. Jack finds his grandparents, no longer has powers, and hides the fact he is coughing up blood. Sam becomes the leader of a new hunter network as he tries to save his brother.
Nick, the former vessel of Lucifer, attempts to resurrect him because he wants to be evil again. Jack becomes soulless and starts having hallucinations of his father Lucifer, complicated his friendship with the brothers. In the end, the brothers and God face off in a shootout. Killing Jack that brings the end of the world, unleashing the souls of Hell and an army of zombies.
The fifteenth and final season starts with the Winchester brothers and Castiel barricaded to protect themselves from the zombies. Jack’s body is possessed by a demon who offers help to the trio. Sam and God’s fates become intertwined. Because of the shooting. This link is exploited to find God’s weakness so they can stop the end of the world, again.
Jack has been resurrected and is murdering fallen angels to regain his power. Jack is being created into a bomb that will kill God and Amara (his sister, the Darkness) simultaneously. Making way for Billie to take over.