Sylph
Encyclopedia Entry:
A wind elemental born from concentrated “wind elements” joined with the “monster’s demonic energy.” They’ve become monsters with a woman’s form. They are capricious and free-spirited monsters like the wind. Ordinarily they hide themselves and fly around the sky with the wind, so they can be quiet difficult to find; however, often times they descend and reveal themselves on a whim.
They form a covenant with a man through the act of sexual intercourse. They men who form a covenant with an elemental in this way are called “elementalists.” It is said that they become able to make use of the sylph’s “power of wind.” Even after the forming of a covenant, they always fly around near their covenanter, suddenly dropping in out of nowhere, unexpectedly kissing, hugging, and fawning on him, likely driving him crazy with their characteristic capriciousness and lack of inhibition.