Sadou Maou

Sadao Maou  was once the Demon King who declared war on Enta Isla in an attempt to take over the four continents. However, due to the actions of the Emilia Justina and her companions, he was forced to escape to Earth, causing him to lose almost all of his powers and living a normal human life, getting a job at McRonalds part time.

An unknown number of years later, Satan became a leader of a Demon Faction and began a great war to annex the rest of the Demon Realm. The struggle lasted from 1741 to 1799, eventually ending with the complete union of the warring tribes as one kingdom. In 1870, he became the Demon King, ruling over his people alongside his Demon Minister Camio while presiding over the tribe leaders within his territories. After completing his quest of uniting the Demon Realm, he realized of a huge problem that came with it. Because he turned the Demon World into a pacific place, he cut the source of demonic energy from his world, thus facing the problem of starvation for the entire demon race. In order to solve this problem, Satan attempted to conquer the land of Enta Isla. The Demon King's desire was to subjugate the humans living there. By doing so he would create a situation in which the humans would hold grudge and several other negative emotions towards the demon race, thus producing enough demonic energy to sustain the Demon World population.