Far Stronger

Anya, once known as the woman Aud, then the demon Anyanka was one of the most powerful beings on Earth. She'd lived in Sweden over a 1000 years before, a minor witch, who's power grew every-time she had sex. Fortunately, she also found that she loved sex and frequently cheated on her husband, Olaf, with...well, everyone. Gangbangs, lesbian orgies, broken marriages, Aud brought trouble to the people of her village.

She likely would have grown and died a normal life, her ability to get stronger each time she had sex would have turned a minor witch into a strong witch, but not one who could have changed the course of history. That was until her husband summoned the demon D'Hoffryn and cursed Aud to live a life of working for the men she had harmed.

Thus she was reborn as the vengeance demon Anyanka, Patron Saint of Scorned Men. Her natural witch powers were bound by an amulet and she was limited to the powers of a vengeance demon. However, she frequently brought comfort as well as wishes to the scorned men. A normal lifetime would not be enough time to acquire power through sex to make a difference, but a thousand years of non-stop fucking?

Those powers though remained safely bound behind her amulet. That was, until, it was destroyed by Giles in the Wishverse.

Now she was loose on Sunnydale. The most powerful witch in the world, with a 1,000 years of knowledge, and a master of sex and seduction. And she had just recruited a future powerful witch to her side through dozens of mind numbing orgasms.