Ganger emerges from living metal brought to Earth by Maya, a refugee whose homeworld Katharos was destroyed by the resource-harvesting Blasters. Fashioned in volcanic fury, this sentient robotic entity possesses independent thought, speech, and the capacity to feel emotions and pain. Maya perished from radiation exposure during his creation, bequeathing her mission of planetary defense to him.

As Earth's primary protector against the Blasters, Ganger operates alone or fused with Kantaro Hoshi, Maya's half-human son. A tractor beam merges Kantaro's consciousness with Ganger's physical form, combining Kantaro's strategic intellect with Ganger's immense strength. Physically, Ganger stands 40 meters tall with a blue-and-red color scheme and wields no innate weapons beyond superhuman power.

He exhibits a stoic reserve, often mentoring the hot-blooded Kantaro. Ganger demonstrates strategic thinking in combat and strong protective instincts toward civilians. His sentience enables complex behaviors: questioning orders, recognizing human emotions, and manipulating situations to protect others, such as using Rie Hayakawa's safety to redirect Kantaro's impulses.

A recurring theme questions Ganger's existential status as a living being despite his mechanical nature. The Blasters' Space Panther entity dismisses him as an "empty shell" during their final confrontation, a claim contradicted by Ganger's evident emotional depth. This confrontation culminates in Ganger's conscious self-destruction to destroy the Blasters' ultimate weapon, sacrificing himself while ensuring Kantaro and Rie's escape via an energy-constructed shuttle.

Ganger's character arc explores mentorship, sacrifice, and the definition of life through his relationships and actions. His dynamic with Kantaro evolves from tactical partnership to profound mutual reliance, while his ultimate sacrifice fulfills his purpose as Earth's defender and completes Maya's original mission.