Zeina belongs to the green alien sea people who serve an ancient undersea civilization. He participates in rescuing Nami Shimaoka from military forces during a beach capture attempt, demonstrating loyalty to their cause. Following setbacks against Doctor Zelvado, Zeina executes a desperate and explicitly suicidal attack on the human antagonist. The mission culminates in Zeina fatally stabbing Zelvado, but he is simultaneously shot during the confrontation, resulting in his death.