Fifteen years prior to the start of the series, N Ma created the Hades Gate to send his entire army to Earth's surface in oder to conquer. The invasion was stopped by the Heavenly Saint Blagel when he sealed N Ma away, however, in turn, N Ma managed to corrupt Blagel to become his servant, turning him into Wolzard. Infershia is structured in a way that the deeper the region is, the stronger members of Infershia resides and therefore, supreme leader of Infershia live in the deepest and the lowest section. Warlords and commanders live above where the supreme leader lives, and minions and agents live above commanders.
The members of Infershia then began working to break the seal so N Ma can spearhead their conquest of the surface world again. However, over time, some of the Infershians began to realize N Ma's true level of insanity and that his obsession with destroying Magitopia was bringing about reckless countless needless deaths, leading to some revolting against N Ma's regime.
After N Ma was destroyed, Hades Goddess Sphinx took over the Infershia to rebuild their world and start a new with Magitopia.
Homever,possibly some of them are still not comply with the new era of peace.