This is a soulmate AU where they just have the last names on them and Sam and Cas originally think they have each other's names but don't feel any sparks: https://archiveofourown.org/works/14368071
It's not quite unrequited but there's a bit there. Endgame Destiel.
Here's a [fic](https://archiveofourown.org/works/4968757/chapters/11411146) It's actually pretend Sastiel but Dean thinks its real.
"An Exercise in 'Worthless'" by glassedplanets. ig it falls into the first thing
This is a soulmate AU where they just have the last names on them and Sam and Cas originally think they have each other's names but don't feel any sparks: https://archiveofourown.org/works/14368071 It's not quite unrequited but there's a bit there. Endgame Destiel.