The succubus is a female demon who loves to have power over male victims during their sleep time. Sometimes this encounter will have strong sexual consequences. The male victim may hope that it is nothing more than a dark dream, but I believe it is more like a terrifying reality.
The scientific explanation for a succubus attack (and other paranormal experiences such as alien abductions) is that a person is experiencing a state of dissociation in which the mental thought processes comes to full awareness even as the rest of the brain is in full REM sleep. The REM sleep will paralyze the body and contributes to the unpleasant and frightening experience. REM can cause erections in males and arousal in females. The mind can blend together the inner dream world with the outer world of sense perception during a dissociated state of mind. However, I believe that the scientific explanation of these events comes up short.
Now a little slant from the folklore world states that the demon can take the form of both a succubus and an incubus (male demon). The succubus first takes the birth seed from the human male and then changes into an incubus to impregnate a human female to create a demonic child, like a Rosemary’s Baby scenario.
A succubus can also be used in a symbiotic relationship, where a knowing victim allows the succubus to use her body to be a vehicle for terror, and in return the succubus drains the victim’s prey (another woman) to weaken the prey so the victim/succubus partner can steal a male from the other woman. This seems like a crazy scenario, but I have heard it over and over again.
Over the years I have heard about many other incubus/succubus encounters and now believe this experience may be happening to the vast majority of humans on this earth and always has. In an infinite universe all is possible.
Sleep tight, only fear will make dreams and your encounters bad. No fear makes you a powerful being, a human being.