I'm looking for a specific vamp Buffy/slayer Spike fic where Buffy is tortured by an evil Angelus as a result of helping Spike stop Acathala. Angelus then sends a feral Buffy to Spike in a crate at the magic box, hoping she will kill the slayer.

If it's a specific fic then post this in the find-a-fic section so this thread isn't deleted

that story sounds really interesting so I hope someone knows it!

The Enlightenment Series by HW.

Buffy must achieve enlightenment before she can return home. PG-13

After Buffy dies, the Scoobies make 'wishes' on how different choices would make things different, and that's one of the 'wishes'.

http://www.catnip.me.uk/enlightenment.html