A succubus is a demon from Hell that occupies a female body. Succubi prey on emotionally weak men and steal their souls through sexual activity. They use the collected soul fragments to gain power and enslave more men. The four pillars of a succubus entity are Lust, Greed, Gluttony, and Selfishness. Succubi use psychological warfare to enslave men.
The physical form of the demon is a small animal about the size of your palm with 4 stumps for legs and a human head that resembles a woman. They don't manifest in any other way save for their true form and you must invite on onto you directly or indirectly.
The succubus wants to make love or have intercourse for one reason: to reproduce using human semen. What happens is the demon climbs onto the male penis and then lays down on it like a dog or cat lays down and then using what could be its genitals to send intense signals of pleasure on the most sensitive parts. To put it simply, it feels amazing. The demon does this to cause a very productive ejaculation (from an intense orgasm) then takes the semen and then impregnate its self, then has a litter which is also succubi and then the matriarch or mother demon orders her offspring to attack the host to speed up the draining of life force and kill the host. Its most of the time fatal.