My Demon (on hold)

Nikki Mikaelson the twin sister of The great evil Niklaus Mikaelson much like her twin was a vampire and a werewolf but was also possessed as by a dream demon who was to week to continue without a vessel so possesed the one that was powerful enough to hold him which was Nikki. Now a tribrid of three differen't creatures she finds herself drawn to a town known as Sunny Dale California unknowingly by the hellmouth that is in the towns school library. She meets the one and only slayer. 'intrigued by the slayer she decides to stick around as the slayers on personal demon helping when she feels like it.
[Takes place in season 2]
Eventual Buffy x g!p OC