overlord: the unbeatable guild (male reader x overlord harem)

Bio: it was created after kyojin traveled to the overlord universe. Making sure that he look Like a player he made a private guild ( he's the only member).

after that he started to create the entire underground and the monsters also he made the boss monsters as Guardians/superior NPC's and Normal monsters as normal npc's.

On the outside he made the guild into a sorta dungeon game. But other players always fail to finish the third area which was waterfall.