In Bruce Wayne's younger years, while training himself to become a vigilante crime-fighter, he travels to Nanda Parbat, a secret monastery in the Hindu Kush region, where he meets its caretaker, O-Sensei, and five other students training in the martial arts; Richard Dragon, Shiva, Jade, Ben Turner and Rip Jagger. O-Sensei eventually entrusts [Shiva] with Soul Breaker, a Muramasa sword in his possession, but otherwise remains secretive about a certain door at the monastery's outer perimeter. One night, [Rip Jagger] penetrates the forbidden door and kills [Jade] with Soul Breaker, which is the key to a mystical gate O-Sensei was guarding. This gate opens to the home dimension of the serpent god Nāga; four of his servants emerge and devour [Rip Jagger] before turning on O-Sensei and his students. Bruce and the others kill the demons, but to close the gate, O-Sensei sacrifices himself by entering Nāga's realm. The chamber then collapses, leaving only the gate intact.
Years later, [Richard Dragon] discovers that millionaire [Jeffrey Burr] is the leader of the Kobra cult and has gained possession of the gate. [Richard Dragon] travels to Gotham City to ask Bruce for help, but they are attacked by a mercenary gang known as the Axe Gang, led by Axe Gang Leader. During this fight, Bruce reveals that he is Batman and that [Schlangenfaust] is looking for Soul Breaker. They head for Gotham Chinatown to inform [Shiva], now the resident crime lord, but the cultists attack them there and [Schlangenfaust] uses the distraction to steal the sword. Needing assistance, the three recruit [Ben Turner], and together they track the cult to a fortified island where they are preparing to open the gate by sacrificing several kidnapped children to Soul Breaker. They also learn from [Ben Turner] that years ago he had tracked Kobra after discovering that [Rip Jagger] was one of their members and that he learned that due to an obscure prophecy Burr means to become Nāga's earthly avatar.
Arriving by plane, Batman, [Richard Dragon], [Shiva] and [Ben Turner] parachute down and penetrate Kobra's defenses through a set of catacombs. However, they encounter [Schlangenfaust], who is revealed as one of Nāga's demonic servants. While Batman and Ben battle [Schlangenfaust], [Richard Dragon] and [Shiva] prevent the sacrifice of the children and engage the cult members. Vanquishing their opponents, they corner Burr at the gate, but Burr turns Soul Breaker against himself, opening the doorway. Nāga emerges, having possessed O-Sensei's body, and swiftly overwhelms the companions. Nāga reveals that [Richard Dragon] is his actual destined host and tries to seduce him with promises of power, but Richard refuses and, with some help from Batman, uses Soul Breaker to banish him by stabbing O-Sensei.
Freed from Nāga's control, O-Sensei bids his students farewell before dying in their arms. To permanently close the gate, Batman enters Nāga's dimension wielding Soul Breaker, with [Richard Dragon], [Shiva], and [Ben Turner] willingly following him. Once the gate has closed, the four prepare for battle against Nāga and his demon horde.
