They ooze sex appeal and carnality in a way that represents Lust as well as the lust for power that evil promises to its prospective followers. They are as handsome as they are arrogant (much to the heroes' annoyance).They hide their demonic soul behind the face of an angel.(Not to be confused with the band of the same name.Or the Esperanto language horror movie.) However, modern fiction writers don't want to use them like that, so typically, the baseline rules are: Incubi and Succubi are almost always treated as a species or type of demons. In some legends, Satan Himself changed shape to be both incubus and succubus.
Oh no, plenty of other monsters and demons have cornered the market on that. They will appear to you as a breathtakingly beautiful woman or handsome man. Nowadays, these are generally referred to as incubus (always male) and succubus (always female).
Some stories actually make them a breed of vampires, since they function similarly (vampires feed on blood for sustenance, incubi/succubi feed on sex), but they are almost always evil. See, Old Scratch wants kids but can't produce human seed, so he becomes a succubus, receives some sperm from a guy, turns into an incubus, and passes it on to a woman.
How this transmits satanic genes is a question not addressed as the theory was invented before Mendel's time, never mind Rosalind Franklin's.
Past comments still remain however and you can still continue to post comments by using a nickname.
Max is the name of this sexy ladyboy and it suits her well.