3. ALL THE TIMES SAM LET DEAN DOWN
Okay, this is going to be a long list. Both brothers have let each other down on several occasions. But Sam has a long list of betrayals. Although it wouldn’t be right to label anything that didn’t align with Dean’s POV as a betrayal such as when he left for Stanford, it was something he was passionate about and chose to pursue it. Also, we cannot label Sam allowing Dean to get bit as a betrayal because it wasn’t the same Sam. His soul was missing and he was devoid of emotions. But it was definitely a betrayal when Sam worked behind Dean’s back to come up with a cure for Mark of Cain. Dean clearly made it clear to Sam to not do anything to save him. But Sam was adamant, his desire claimed the life of Charlie which shook Dean to his core.
But perhaps the worst of Sam came when Dean was serving time in the underworld. Sam grew closer to a demon named Ruby who made him addicted to the demon blood and kept pushing him to the dark side. Ruby was manipulating Sam for selfish reasons. Even Dean tried his best to get his brother off the addiction. But it didn’t change things and it escalated to the point when the brothers had a fight where Dean tells Sam that if he leaves then he can never return back again. Sam still chooses Ruby and decides to walk out on Dean.
2. MARY WORKING WITH BRITISH MEN OF LETTERS
Mary’s story arc in seasons 12-14 of the Supernatural has received mixed reviews from fans. When Mary returned, she walked into a new world and struggled to keep up with the changes. Her boys are now grown-up adults. Mary’s confusion is understandable, but her decision to align with the British Men of Letters is totally surprising. When she was tasked with retrieving the colt from Ramiel when she sought the help of her boys and Castiel. However, she didn’t reveal the truth of her mission to the boys and Castiel. They believe her story and walk into the house of a prince of hell. Castiel is mortally wounded and if it wasn’t for Crowley who came to their rescue at the right time, Castiel would have gone to the Empty earlier than expected. Dean is heartbroken when he learned that Mary chose Men of Letters over him and Sam. What’s even worse was her affiliation with Arthur Ketch.
1. CHUCK IS THE BIG BAD
Chuck first appeared in Season 4 as Chuck Shurley, taking the guise of a writer & prophet. He was closely watching the events that could have led to the apocalypse, but the Winchesters prevented it. Chuck would disappear again and would resurface when Amara started causing all sorts of chaos. He revealed his true nature to the Winchesters and asked for their help. Chuck assembled a team of the boys, Crowley, Rowena, and Lucifer along with the factions of angels and demons in order to entrap Amara. Chuck would then return, telling the Team Free Will that eliminating Jack is the only way to help him. But the boys saw through his manipulation. His biggest betrayal came when he caused the demise of Jack and decided to end all his worlds one by one, punishing humanity, and resetting the entire universe.