I've recently been re-reading some of my Spander favourites but there's one fic that I cannot remember the name of and I just can't find it! I might be combining fics but here's what I remember...
It was years on and Xander had taught himself magic (he was living away from the Hellmouth at this point; he left after a fling with Giles that ended rather badly, poor Xan!), and could do things that no one else could, just because he hadn't known that he wasn't supposed to be able to do certain things.
He and Spike end up together, of course, and then Oz and Wesley show up (separately). I can't remember how or why Oz showed up but Wesley was supposed to be a seer for Angel only Angel was ignoring him or something, I can't quite remember. They end up venturing to Sunnydale after Wesley gets a vision. Xander makes them all up with amulets and magic to look like completely different people so they won't be recognized by the remaining Scooby-gang (and Angel).
Things are, of course, crazy when they get there and at one point Buffy has a complete mental breakdown (the characterizations were a little nuts by this point but I'd still like to find the fic!), and there's this big fight in the rain... I can remember more if anyone is nearly there but I think this should maybe be enough?
Anybody? Anybody? It's really bugging me and I cannot for the life of me find it!!
ETA: Found! It's the "Not the Only One" series by Gypsy Gray. Thanks to chibi_kachi who found me a link!