Dungeon Battle Royale

One day, every person on Earth simultaneously receives a cryptic email announcing the commencement of the World Salvation Project. The message reveals that humanity will be categorized into one of three alignments: Law, Chaos, or Neutral. Shion Kurosaki, a solitary university freshman, is assigned to the Chaos faction. This designation transforms him into a Demon Lord in the newly formed world, tasking him with constructing a dungeon, populating it with monsters, and defending against assaults from heroes aligned with Law. Thus begins his journey as a dungeon builder.