Poseidon

Poseidon, God of the Sea is a pro-monster divinity of the Monster Girl Encyclopedia world. Similar to the greek god of the same name, Poseidon rules over all the world's oceans and commands all the creatures living within them. Poseidon was originally aligned with the Chief God and Heaven but, was later monsterized and joined forces with the Demon Lord. As the patron of an ocean home to monster girls, Poseidon devotes her time to making life beneath the waves amenable to her worshipers and their husbands. Instrumental in this are her sea bishops: seahorse monsters who can confer on humans the permanent ability to breathe underwater.

Poseidon's change of heart and her eventual alignment with the Demon Lord was not a direct consequence of demonic energy corruption leading to monsterization, but rather a conscious decision to defect. Poseidon grew disillusioned as a result of the Chief God's orders to kill humans with storms and tsunamis and the Chief God killing sea monsters and devotees of the sea god. Since her defection, being dragged under the waves no longer ends in death by drowning: Poseidon's magic monsterizes women into nereids, and sustains men until one of her devotees arrives to rescue him. The sea god still calls down great storms to shipwreck sailors, but does so in order to provide male husbands for the monster girls of the sea.

During the age of the former Demon Lord, Poseidon was heavily involved in a great war between the forces of Heaven and the demons of chaos. These eldritch demons were sealed in the deepest part of the sea, and even today, thousands of years later, this abyssal zone lies beyond reach of Poseidon's influence.