Zeus, the omniscient and omnipotent god, had his soul sealed in a human body by his children, Apollo, Athena, Ares, and Artemis, because of his unmanageable behavior. The soul of Zeus, which had been sealed in a human body and reincarnating for 1,000 years, was inhabiting an Egyptian slave child "Chetho," until Chet's life was threatened due to an incident. That was when the thousand-year seal was broken, and the soul of Zeus was unleashed on earth once again.
(Source: Pixiv Comic, translated)