Two Realms: I Have a Dragon in the Dungeon

After traveling to a fantasy world, one night, Leon suddenly awakened a dragon clone in the dungeon, which could not only strengthen simultaneously, but also transfer resources to each other. The underground city is a forbidden place of death for humans. It is full of crazy monsters, imperceptible traps and deadly poisonous gases. Even if you are lucky enough to survive, you will have to face the fear of hunger and disease. However, for Leon, who has the incarnation of a dragon, this is paradise. The dragon clones devour various monsters in the dungeon and evolve infinitely, transmit precious resources hidden deep in the maze to the outside world, and find powerful relics from the ruins of lost ancient civilizations... The human body uses the magical knowledge of the surface world to carry out dimensionality reduction strikes in the dungeon! Unknowingly, the reputation of the dragon clone spread to every corner of the underground city, and all underground creatures surrendered, and even established a magnificent underground kingdom... "Honored and strongest brave man, Your Excellency Leon, our Adventurer Association has detected the appearance of a demon dragon king in the dungeon. We hereby implore you to serve as the leader of the adventure group and defeat the demon dragon to save the world." Leon: "???"