Demigods were considered the superior/noble class and controlled the lower class humans.
In ancient past, an advanced civilization known as Shinkoku Trastrium rose to power and unified the nations of Earth, then known as Gaea. Trastrium was a hierarchical empire, under which unaltered mortal humans comprised the lower classes, which was ruled by near-immortal genetically/cybernetically altered humans called Demigods. The Emperor was the beloved figurehead of Trastrium and commanded the demigod military through his Eight Guardian Generals, an elite group of demigod warriors charged with protecting both Shinkoku and Gaea. The demigods controlled the supply of mantra, a powerful energy source that is derived from emotions. Only demigods could manipulate mantra, which powers most, if not all their advanced technology and allowed the demigods to augment their physical abilities. The demigods promoted a new world religion based around their worship, and made great advances in science from the resulting influx of mantra.
Trastrium’s growth came at the cost of critical levels of pollution and overpopulation, which forced Gaea into action. The planet unleashed its natural immune system to restore balance to the world: the Gohma. In the form of endless hordes of mutated animals and creatures, the Gohma’s attempts to cleanse the world were barely fought off by Trastrium forces over millennia, with neither side possessing a way to decisively defeat the other. This eternal conflict became known as the War of Creation.
Asura was the newly appointed Demigod Guardian General of Wrath to the Eight Guardian Generals. Prior to the events of the game, his daughter Mithra was chosen by Emperor Strada, the 127th Emperor of Shinkoku, to be Trastrium’s Priestess, the ultimate amplifier of mantra and morale for the Demigods in the War of Creation. Asura grudgingly approved, and went on to fight many battles with the help of his daughter’s prayers.
The War of Creation dragged on, punctuated every few thousand years with the awakening of Vlitra, a continent-sized Gohma that was the embodiment of the planet’s rage towards Trastrium and the Demigods. While suppressed by succeeding generations of Generals and billions of warriors, Vlitra and the Gohma eventually gained enough power to wipe out humanity and the demigods at the time of Vlitra's next awakening. Fearing defeat, the demigods begin construction of the Karma Fortress, an orbital space station which housed the Brahmastra, a gigantic laser powered by Mantra, which could suppress the Gohma's presence over long periods of time.
With the coup' de etat of the the latest Emperor by Deus, the leader of the Eight Guardian Generals, the Empire of Shikoku Trastrium was completely overthrown and fell under the absolute control of the Seven Deities with Deus as the new ruler. However, due to events cause by the betrayed demigod, Asura, and the efforts of Yasha, former member Seven Deities, the empire of Shinkoku Trastium had been been thrown into disarray and eventually fell in to ruins.