Succubus

Succubus is an evil spirit who steals men's life force by seducing them in their sleep. In medieval times and Western tradition, succubi were thought to take the form of beautiful women to drain a man’s energy during sex- either for his health or steal this essence as sustenance for her own survival. You'll often see this in hentai anime, manga, game, or eroge. Succubus characters need to extract sexual energy or semen from their partners in order to live and maintain their own human forms.

Itadaki! Seieki is a succubus hentai anime.
Last night, I had sex with a succubus. My penis is so painful now.