The Reformation of the World as Overseen by a Realist Demon King, Vol. 7 (manga)

With Eve, Toshizou, and Jeanne by his side, brand-new Demon King Astaroth has already bested three other Demon Kings on his way to mastering and reforming the world. His next target is Zagan, a monstrous Demon King, but Zagan has a powerful hero on his side too--the son of Genghis Khan