Chaos bleeds - James A. Moore

Buffy Summers makes enemies. Powerful ones. She can't avoid it -- it goes with the job of being the Slayer, the one girl in all the world with the strength to destroy vampires and demons. Those who fall foul of her and live to tell the tale tend to harbour resentment and thoughts of revenge. One such is Ethan Rayne; devious, treacherous and suave. Ethan has a history with Giles, too. Their dabbling in the occult in their wilder student days led Giles to accept his destiny as a Watcher and set Ethan firmly on the path to darkness. Now Ethan returns to Sunnydale -- surprisingly, asking for Buffy's help. He seems to have roused The First, the ancient evil that predates humankind. But then The First offers Ethan a deal which will gain him ultimate power. All Ethan has to do in exchange is to lure Buffy into battle...