The Powers That Be need a new warrior. Set just prior to BtVS S5. A/N: A moment of random word association and this is what I came up with.
The Powers were concerned about the dimension containing Earth. Dark forces were rising; forces that threatened the tenuous balance between good and evil. Although neither could exist without the other - for without illumination there are no shadows - the two sides were eternally locked in a struggle for supremacy. The Powers were charged with the preservation of the fragile equilibrium, lest one faction grow too strong and, in so doing, extinguish the existence of both.
Countless times had the legions of darkness lured to their side those who had previously dwelled in the light: they who succumbed to the siren calls of avarice, despair or the lust for power, who strove for Ascension, or lost their souls to vampires intent on the propagation of their own kind. Fewer were the times that a creature made the return journey and it was for the tasks of bringing light out of darkness that the Powers found their intervention most often required.
The Powers observed the events unfolding on Earth and the future to which they would lead, and they pondered. That another warrior was needed was certain. The difficulty lay in where to find one. There were no more souled vampires for the envoy Whistler to set on the path to redemption. An unprecedented two Slayers already existed when there should only have been one. And, though she herself was not yet aware of it, the human Seer's visions were taking an irreparable toll on her body. This new warrior would have to come from a different quarter.
The Powers thought deeper, saw further, and found that which they sought. There was another who could be changed. The darkness within him was strong, but there was something else as well - the capacity for love. His circumstances dictated that he live amongst mortals and his connections to them had already begun to form. In another part of the world, the brethren of an ancient sect searched for a hiding place for that which they had sworn to protect. Both ends could be realised with the same means. It was an elegant solution.
There are many ways to kill a vampire: beheading, sunlight, fire, a wooden stake through the heart. Sometimes, however, it is the dose that makes the poison. While killing the vampire outright would incrementally reduce the burden of evil in the world, it was the Powers' desire to burn away the monster, bit by bit, without destroying the man. The vampire would be sent the muted light of daybreak to end his dark night - the sunrise that would dispel his shadows - and that which already existed within would be freed to shine forth.
Shrouded heads nodded in agreement. No words were spoken but all shared the thoughts of one. Each entity reached out its hand and, as their fingertips touched, it was begun.
Dawn was coming to Sunnydale.