From Seven Seas:
At the end of his life, after decades of painstaking research, Aur’s quest for ultimate power is within reach. But first, he must die. Now, reborn into a magical world as the Demon King, he uses his newfound abilities to make his dark visions a reality. Upon summoning an alluring succubus known as Lilu to serve him, he immediately begins the task of creating a dungeon - an underground kingdom of his own, filled with all manner of fantastical beasts. As Aur crafts the intricate and dangerous world of his dungeon, he’ll learn what it takes to become a true Demon King, with all the pleasures, troubles, and trials that come with it. And his enemies will cower in fear.