Without the fuel that feeds the fire

Without that which is her hearts desire

Slowly shall she fade away

Into mist and there she'll stay- From the Big Book of Evil Beasties Most Foul.

Buffy Meets Twilight

Buffy looked at Edward then at Bella. She staked Edward. With a scream Bella turned into mist and faded away. Life in Forks returned to normal as all traces of the evil beastie known as a Mary-Sue faded from the town folks lives.