I know the Buffyverse is virtually a dying breed, but a few friends and I have been dabbling with some period based stuff in one of our GPSLs and are looking to potentially have another player write for Drusilla or Spike. The line initially takes place between season one and two of AtS with a different spin on Darla's resurrection as well as some AU elements from season one.
Chronologically it bounces back and forth between modern day Los Angeles at the beginning of season two (2000-2001) and various points of the eighteenth/nineteenth century via flashbacks. As for the AU stuff - Penn was never dusted in season one and was merely chased out of town. The plot so far has Darla, Drusilla and (now) Penn terrorizing LA and attempting to rebuild the Order of Aurelius. Spike, Buffy and Faith have been recurring characters as well.
The writing is done in journals, google docs and on AIM.
( *Update* There is potentially a new storyline in production. PM me for any details on the plot/available characters. )