Yuusha ni Horobosareru dake no Kantan na Oshigoto desu

Due to the schemes of the mysterious existence "Demon God," Ryou Nakajima is reincarnated in another world as the Demon King Vermudol. However, he ends up in a place that is embroiled in turmoil and chaos. If the birth of a new Demon King were to be known by the humans, a hero would surely come to defeat him soon. In order to change his fate of dying at the hero's hand, Demon King Vermudol sets out to quickly unify the continent with his cheat authority!

(Source: AlphaPolis, translated)