Something Blue's still my favourite.
"What are you looking at, Master?" the little demonic minion questioned, groveling at the edge of the reflecting pool. "Is it your little witch again?"
"Oh, yes, loyal one. It is always a pleasure to observe her and the pain she has inflicted."
"Tell me," the little one pleaded. "Tell me again the tale of the foolish witch."
"All right." He leaned back into the flames. "Two years ago, as the human years pass, the little witch called me in her selfish pain, asking that her will be done. And I, kind immortal that I am, granted her heart's desire. Three wishes she knew of, that the Watcher be blinded, the mortal attract demons, and the vampire and slayer be wed."
"But she thought she'd reversed these, didn't she Master?" The little head bobbed up and down at the retelling of the familiar story.
"Yes, she thought they were reversed by D'Hoffryn." He smiled his most cruel smile. "As if that simpering idiot could hope to contend with my magic. And yet I let them both believe it true."
"But is wasn't true, was it? Not true at all."
"No, sweet toady," he patted the little head, "not true at all. For the Watcher is still blind, leaving his charge without seeing this is the time she would need him most. The human's life is intertwined with demons, the woman he loves, the vampire, the destroyer at his wedding; his life will never be lived in simple mortality. The vampire and the slayer, now that was easy. They are wed in their hearts, though he would reject it and she would deny it. That only required a gentle push on my part."
"But there was another wish, wasn't there, Master? One she didn't even know she made."
"Yes, little one, one more wish. The most delicious wish of all." He steepled his fingers and licked his lips.
The little demon jumped up and down with anticipation at the telling of his favorite part. "What did she say, Master? What did the witch say?"
"She said, 'I think we're all doomed to badness.'"