Zero is the son of Ultraseven. He was trained under Leo after he was banished from the Land of Light by his father for attempting to take the Plasma Spark for himself. His training ultimately led to his redemption in his battle with Belial, who would become Zero’s archnemesis.

Strong-Corona is Zero’s strength form, a byproduct of his fusion into Saga with Dyna and Cosmos, and is taken from their Strong Type and Corona Mode respectively. It uses brute force and fiery abilities.