During an earthquake, a system tried to make a dungeon out of a pocket of mana. However, the earthquake disrupted it and damaged the dungeon, making it unable to get more mana naturally. Due to these issues, the system contacted the local administrator to resolve the issue. The administrator told the dungeon how to get more mana through souls obtained using demons and left with a parting gift, leaving the dungeon to its devices. Now, the dungeon must find a way to have people make deals with the demons it makes to get their souls. Unfortunately, the first demons it can make are grotesque, slobbering mouths.

July 24 2022, adjusted synopsis to work better.