Roy used the method of soul employment to summon hundreds of low-level demons from the upper levels of the Abyss and handed them over to Benia to lead them to begin building a new demon city.
In fact, Roy could directly create the demon city by himself with the flowing brightness flames, but he did not do so. Instead, he let the demons build it because only demons could build pure demon-style buildings.
On the frozen soil and icy plain, digging soil and rocks was very energy consuming. But this time, the demon worm had contributed greatly. With its powerful digging ability, it placed the soft underground soil in its mouth and allowed the demons to have construction materials.