Synopsis: How to Build a Dungeon: Book of the Demon King

Due to a strong animosity towards humans and their inclination for deceit, Oulu had dedicated his entire existence to attaining the strength and influence necessary to become the Maou. After accomplishing his aspiration, he enlisted the assistance of the succubus Lir to assist him in constructing an extensive dungeon and establishing his own kingdom. This signaled the inception of a tale featuring a cynical Maou who strives to control the planet, a wicked and convoluted harem tale that takes shape right before us.