Orgun is an alien warrior unit created by the Evoluders, a mechanically advanced species dedicated to destroying civilizations across space. As a high-ranking Evoluder, he eventually rejects this destructive purpose and flees to Earth. There, he seeks answers about his own origin and intends to warn humanity of the impending invasion.

Near death after an attack on the Moon, Orgun transmits dream signals that forge a psychic and physical bond with Tomoru Shindo, a college student. This bond merges their existences, enabling Tomoru to synchronize with and pilot Orgun’s biomechanical form in defense of Earth.

Orgun functions as a powerful suit of armor, capable of enhanced speed and equipped with weaponry including a double-sided lance, wrist-mounted swords, and a forehead-mounted Photon Beam cannon that can destroy multiple city blocks. His ultimate attack, the Grand Cruciform, gathers all available energy into a single, massive blast.

He discovers that Earth is the original homeworld of the Evoluders, which deepens his resolve to protect it and redeem his own people. In a final confrontation, Orgun faces Commander Zoa, the true military leader of the Evoluders, and sacrifices his life by using the Grand Cruciform to neutralize Zoa’s antimatter cannon.

In a separate continuity, Orgun is depicted as a droid created by the L.O.S.R. organization to serve as an aide to Sigma. In this incarnation, he is a deadly warrior who follows orders without question, showing no regard for honor or mercy. He shares a brother-like connection with another droid unit named Blade.

After the main conflict, Orgun’s remains are recovered and placed on display in a museum as a relic of the battle for Earth.