Guy Zelbert holds the rank of Admiral within the Ocean Empire's military, serving directly under its leader, Hell Deathbird. He faithfully executes his duties within this command structure until Deathbird orders the destruction of an underwater city, causing mass casualties among the Water World Men. This event leads Zelbert to conclude Deathbird has crossed a moral boundary. In response, Zelbert orchestrates a coup d'état to overthrow his commander. The coup fails. Following this defeat, Zelbert surrenders to the crew of the submarine Super 99, seeking an alliance against Deathbird. His subsequent direct confrontation with Deathbird results in his death.