hello! I got this idea for a while and I was thinking this was a good place to post it:

Dean and Cas arrived to purgatory along with their bodies, even though it is impled only the souls of monsters inhabit that plane.

somehow Sam manages to fin a way to open a portal to purgatory and rescue Dean and Cas, but something happens in the transition and now the two of them have...fussed together; their personalites, their souls and even their looks, they are now merged into one single person.

I want to read about Sam's reaction to this new guy who at times acts like Sam's brother, but others is compeltely allien and soccially awkward like Cas.
also it'd be nice to see the part that is Dean and how it tries to make his 'brother' better.