It was a Post Gift AU where Anya is paralyzed from the waste down and eventually dies, Giles leaves and Spike helps Xan deal with mounting responsibilites a lot. Oh, and it turns out Willow, who is acting weird, is possessed by a demon that comes through the portal right before Buffy jumps. It's kinda long and it seemed to be finished. I think I found it by accident and can't remember the website.
Thanks for the assist!