Black Market Dungeon [240915][RJ01251245]

A vast, labyrinthine structure was discovered beneath a ruin. However, these were no ordinary ruins.
It was filled with hidden treasures and teeming with ferocious monsters.
The world underwent rapid changes.
Rare treasures and unknown materials were obtained from the monsters.
Research into powerful weapons, tools, and magic advanced, and individuals and countries alike continued to pursue their ambitions.
Towns and villages around the dungeon began to flourish, and many people dreamed of striking it rich.
Inns, tool shops, and blacksmiths were particularly valued and could grow as large as desired with effort.
In such a world, a man appeared, grinning at the dungeon before him.