To call the season 5 finale intensely “swan song” would be quite an understatement. After Sam devises a plan to defeat Lucifer (Mark Pellegrino) once and for all, he becomes possessed so he can throw himself and Lucifer in a cage and prevent the apocalypse. As you can imagine, things got out of hand in no time, and before the credits rolled, Redditors like u/l0s3r_06 couldn’t help but get emotional about it all. Arguably the biggest reason was the connection between Sam and Dean and the moments it evoked, as u/Used-Violinist-6244 pointed out in a comment that ran through the most upsetting moments.
People in the replies also noted that the end of season five felt like a series finale, and in reality they’re not that far off, so to speak. Dean Winchester himself, Jensen Ackles, has explained that Eric Kripke had a five-year plan for the show from the start (via Cheat Sheet). “Eric said, ‘I have the plan. I have everything. And then we just kept picking up steam in Season 4 and picked up a little bit more steam in Season 5,” Ackles said, but his success couldn’t be ignored. Kripke left the show after season 5, and she trotted on another 10 seasons without him.
No matter where you are in the later seasons of “Supernatural” and its controversial ending, it’s hard to deny that the first five seasons and the fifth-season finale weren’t excellent television — despite the ability of “Swan Song” to do that to get waterworks flowing.