A remnant of the past...
We know little about the succubi. Some legends say that they were created by Sanghin, the Daedra god of lust, to entertain him.
Satisfied with them, he had given them the permission to spread the lust throughout the world. Inspite of there appearance, Succubi are not evil and hate hurting people they need, but NEVER UNDERESTIMATE THEM they can hit you severely. After the Oblivion crisis, the number of Succubi fell; many of them have remained stuck in Oblivion. But it is said that some of them know the way to return to Mundus ...