This demon city built by Xeron detonating a volcano did not seem to have a name.
To the demons, it was only an outpost for attacking Erathia. It was on the border, and with the extension of the frontlines, reinforcements from this city would become slower and slower. In other words, this city, in Xeron's original plan, was going to be abandoned.
Precisely because of this, when Roy returned to this city, there were no high-rank demons stationed in it, and only a few little demons were left in this city. When he left, Ignatius did not bring these little demons, leaving them as coolies and defense forces. From this, it was apparent that the demons would abandon this place in the future.