Even though Supernatural already got one short-lived spinoff, one storyline from season 6 would make an incredibly epic spinoff series – but, unfortunately, it will likely never happen now after the doomed The Winchesters spinoff. Over 15 seasons, Supernatural was no stranger to huge, sprawling storylines with grand consequences. The overarching stakes of most seasons involved a literal world-ending threat, and, upon occasion, Heaven, Hell, and Purgatory ending, too. It’s enough that the final season even set up a hypothetical Supernatural season 16.

https://screenrant.com/supernatural-season-6-war-in-heaven-epic-spinoff-idea-op-ed/