Robert Dunham

A businessman with a disfigured face obtains a lifelike mask from his doctor, but the mask starts altering his personality.

Inventor Goro Ibuki creates a humanoid robot named Jet Jaguar. It is soon seized by an undersea race of people called the Seatopians. Using Jet Jaguar as a guide, the Seatopians send Megalon as vengeance for the nuclear tests that have devastated their society.