The ancient dragon Magranalus.

Residing on the seventy-fourth floor of the A-rank dungeon known as the *Devil's Prison*, located near the royal capital of the Udon Kingdom, Tenkaashi.

Its true identity is that of an ancient dragon, one of the Eight Great Dragon Kings. However, it had forgotten its original purpose and transformed into a being that slaughters adventurers, heroes, and challengers who dare to explore the *Devil's Prison*.

At that time, Yuu and his companions, who were leveling up while exploring, would encounter this ancient dragon.

Its strength was unimaginable. The sheer force of the dragon casually swinging its …