Emerging as primary antagonist following Big Gold's defeat, Neos Gold declares herself Big Gold's core terminal and successor. After initiating a conflict with Iczer-1 that leaves both severely weakened and unable to fight directly, Neos Gold relies on subordinates to execute her plans. She commands four primary agents—Fiber, Insect, Golem, and Bigro—to spearhead her invasion.

Her assault on Earth commences with seizing orbital satellite weapons, devastating global defense forces while deploying alien insects as biological weapons. Establishing an Earth base, she coordinates further attacks against humanity's remnants and their protectors. Mid-conflict, she creates Atros, a clone of Iczer-3 forged from stolen Iczelio Energy. Neos Gold presents herself as Atros's creator and mother, though this relationship is purely manipulative; she views Atros solely as a weapon, showing no genuine affection. She demands absolute obedience, punishing failures with physical discipline and threats of destruction, ultimately discarding Atros as ineffective and replacing her with a reprogrammed Iczer-2.

Demonstrating strategic pettiness, Neos Gold prolongs human suffering specifically to antagonize the recovering Iczer-1. Her tactics involve remote battle oversight from her fortress, later escalating to direct intervention using an experimental powered suit. This fortress is shielded by a potent energy barrier requiring combined forces to breach. In the final confrontation, she mortally wounds Atros for betrayal and is ultimately defeated by the combined efforts of Iczer-3, Nagisa Kasumi, and the crew of the battleship Queen Fuji.