Encyclopedia Entry:
A water elemental born from concentrated “water elements” joined with the “monsters’ magical energy.” They’ve become monsters with a woman’s form. They are monsters that have beautiful bodies that are translucent like the water they are made of, and have a pure, kind heart with a gentle disposition. Normally they dwell near sources of water like lakes and springs, and they never aggressively attack humans.
They form a pact with a man through the act of sexual intercourse. The 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 undine’s power over water. It also is said that the undines stay at the side of the ones who make the covenant like a devoted lover.
To begin with, water elementals look fondly at romantic relations between men and women. On top of that, the monsters’ magical energy inside of them gives them a strong urge to seek intercourse with a man. Obeying their instincts, when they find a man they like, they seek to form a covenant with this man, and try to seduce him. Even after binding the covenant, in order for the covenanter to use the power of water, he must have intercourse with the elemental beforehand. It is necessary to draw out the power of water from each other’s bodies. During this intercourse, the elemental is able to receive the covenanter’s spirit energy, and her own power is enhanced because of it. The power of water usable by the covenanter grows more potent depending on the power of the undine. However, at the same time, in proportion to the amount of spirit energy they take in, the elemental monsters’ magical energy grows more condensed and powerful, eventually contaminating her body.