Long before humans arrived on Planet Zi, Ancient Zoidians clashed with one another in brutal battles. Of these clans of humanoids, several nations existed. But one stood above most. The Zenebas Empire.

The unification of the Central Continent by King Helic in ZAC 1955 inadvertently caused a chain of events that sparked the beginnings of the Zenebas Empire. Helic had two sons by two different wives; the first was his heir, Helic II. The second, borne by Guylos' sister, was Zenebas Muroa.

King Helic died in ZAC 1978, which naturally made Helic II the successor to the throne of the new Helic Republic, while Zenebas was then appointed as the new commander and leader of the military brass.The late King Helic was able to leave behind instructions to his sons. In short, his dying wish was for them to work together and cover for each other’s weaknesses. In short, to build a long, lasting republic that would withstand the test of time. However, Zenebas had other motives. He grew increasingly impatient with the Republic's pacifist policies. He even attempted to persuade his brother into believing that a more aggressive approach was necessary to protect the nation's safety. Naturally heated debates, constant pressure, and poor tensions would soon give way to the Republic banishing Zenebas—and in retaliation, caused him to form his own Empire.

In the beginning, wars would break out between both factions, however most battles were small in scale and saw minimal casualties in each encounter. All that would change in ZAC 2029. A Ship, coming from earth crashed on planet Zi containing a species that the Zoidians had never seen before. Humans. While strikingly similiar in appearance, their genetic makeup was considerably less metallic and possessed no psychic/telepathic abilities. Yet humans had the potential to thrive alongside their Zoidian neighbors. And thrive they did. The survivors of the crash would soon befriend both the Helic Republic, and the Zenebas Empire and assimilate into their culture. But this had serious repercussions. Soon, a major arms race sparked, which lead to one of the deadliest wars on the planet. And their deadliest creation. The Death Saurer.

A Shadow Organization made of militarized spies, assassins, informants, and warriors. Terra Geist was a mysterious faction who's sole purpose was to bring back the now extinct Zenebas Empire. With it, those of Terra Geist would plan to rule all of Zi and perhaps expand their reaches to space. While other Empires such as Guylos now existed, Zenebas was far more brutal and aggressive. With tactics which meant total and absolute control through the Emperor, and employing powerful zoids such as the Deathsaurer~ Their reign of terror could very well mean the end of the world for Planet Zi.