In the world of Sand Land, Général Zeus stands as the primary antagonist and the true power behind the throne of the kingdom. While an ineffective king officially rules, Zeus holds the genuine authority as the supreme commander of the Sand Land Royal Army. His backstory is rooted in a devastating act of betrayal that occurred thirty years before the main events. A race of small, blue beings known as the Picchi had created a device capable of producing water, powered by a volatile crystal called Aquanium. Under the false pretense that the device was a weapon of mass destruction, Zeus ordered a military attack on the Picchi. This attack caused a catastrophic explosion that killed countless civilians, many Picchi, and several high-ranking officers, including General Aro and the wife of General Shiba. Zeus secretly orchestrated this event to eliminate his rivals and seize control of the kingdom’s water supply, solidifying his power.

Zeus possesses a deeply manipulative, deceitful, and power-hungry personality. He is willing to sacrifice anyone, including his own soldiers, to maintain his control over Sand Land. He uses propaganda and mass media to spread disinformation, placing a large bounty on the protagonists to turn the public against them. His ultimate goal is absolute authority, which he achieves by monopolizing the region's water sources. By damming a natural spring, he prevents water from flowing into Sand Land, forcing civilians to pay exorbitant fees to the royal army for their own water reserves. To prolong his life and maintain his grip on power, Zeus has converted his aging body into a cyborg, relying on cybernetic enhancements and often seen using a floating robotic lift.

In the story, Zeus serves as the main obstacle for the protagonists, a group consisting of the demon prince Beelzebub, his assistant Thief, and the aging sheriff Rao. Zeus is also the archenemy of Rao, who was once a celebrated general of the royal army known as General Shiva. Rao was believed to have died in the great explosion Zeus engineered, but he survived and has spent decades in hiding, finally seeking revenge once he learns the truth. Another key relationship is with General Are, a young and skilled officer under Zeus’s command. Zeus has mentored and manipulated Are for years, carefully hiding his own role in the explosion that killed Are’s father, General Aro. When Are begins to question the official story, Zeus immediately orders him detained, revealing his willingness to discard anyone who threatens his regime.

Throughout the narrative, Zeus's development is less about personal change and more about the increasing desperation of his schemes as his control is threatened. When the protagonists discover the dam and the truth of the water shortage, Zeus deploys his most dangerous assets, a squadron of experimental, bomb-laden Insect-Men soldiers, to destroy them. His final confrontation ends in his defeat. The outcomes differ by adaptation. In the original manga, General Are fires a tank cannon at Zeus’s cyborg body, causing a malfunction that results in a fatal explosion. In the anime, Zeus ejects from his damaged body and attempts to detonate the remaining Insect-Men from a safe distance. However, Beelzebub recovers, physically stops the detonation, and punches Zeus sky-high, where he disappears from the story for good. His notable abilities include his strategic military mind, his cybernetic body which grants him enhanced durability and contains hidden explosive devices, and his absolute control over the Sand Land Royal Army and its advanced weaponry.