Arajin to Aribaba

Dispersed around the world, there are several bizarre labyrinths hiding incredible treasures within them. These mysterious places, known as "Dungeons," are said to be the work of Magi, a class of rare magicians, who also help people build their empires by guiding them to a dungeon. Djinns, supernatural beings that rule over the labyrinths, grant successful conquerors access to their immense power and choose them as potential king candidates to rule the world. (myanimelist.net)