General Zeu commands the Sand Land Royal Army as its supreme leader, wielding true power while the king serves as his figurehead. To sustain his failing body, he relies on cybernetic enhancements and a floating robotic lift. Thirty years prior, he orchestrated an attack on the Picchi people, exploiting their volatile Aquanium-powered water device. Under the false pretense of a weapon threat, he ordered General Shiba (later Sheriff Rao) to destroy their facility. This triggered a catastrophic explosion, eliminating rivals like General Aro and Shiba's wife, along with countless civilians and soldiers, securing Zeu's water monopoly. Unaware that Shiba survived and uncovered the truth, Zeu perpetuates water scarcity by damming natural sources, enforcing flight bans to hide the dam, and charging exorbitant fees. He manipulates General Are, fostering his career while concealing his role in the explosion that killed Are's father. Confronted by Rao, the demon prince Beelzebub, and allies, Zeu deploys explosive experimental Insect-Men soldiers against them. At the dam's final battle, he detonates the Insect-Men and activates his cyborg body's self-destruct to eliminate all threats.

In the manga, General Are intercepts this plan by firing a tank cannon at Zeu's cyborg form, causing a malfunction and fatal explosion. In anime and video game adaptations, Zeu survives the initial assault, ejects from his damaged body, and attempts to detonate remaining Insect-Men to destroy the dam. Beelzebub intervenes, physically halting the detonation and punching Zeu skyward, where he vanishes. His defeat enables the dam's destruction, restoring water to Sand Land and ending his rule.

Zeu exhibits extreme manipulation, deceit, and hunger for power. He sacrifices subordinates without hesitation, suppresses dissent through propaganda and bounties, and exploits others' trust to maintain authority. His actions stem purely from a desire for absolute control over Sand Land's resources and populace, devoid of ethical considerations.