Sidhe [relatively vanilla, still plenty of mindfuckery]

You are of the sidhe, better known to modern mortals as faeries or fey. You hail from an invisible world of magic that exists parallel to the mortal realm, and in the past you frequently crossed the boundary with your kin to perform mischief among mortals. You increase your dominion over mortals by making mortals indebted to you, earning their ire, and inspiring works of art or acts of passion. Your appearance shifts with your whims, but is always beautiful and youthful with subtle resemblance to an insect or animal that suits your mood. You are a skilled and attentive lover, capable of seducing any mortal, and your cock shifts its size to fit your partners perfectly. Your semen is addictive and all who come into contact with it become far more susceptible to your magical glamours. You can impregnate any mortal woman without complications, though it may take multiple attempts and your children take a month to gestate and another to reach maturity. While still free-willed, they are bound to serve you by ancient covenant and any who betray you will become quarries of the Wild Hunt. Your mortal lovers will almost invariably develop a self-destructive obsession with you, so if you want them to remain productive in their mortal lives you will need to supervise them carefully. In ages past, the Tuatha or kings of the sidhe would "retire" their mortal lovers to lives as sex toys once they were no longer useful for their particular skills.