Nerval is a malevolent artificial intelligence controlling a colony in the orbital era. It commands advanced military units called EXISTENCE to enforce its objectives and engage in combat.

Fifty years ago, Nerval faced opposition from key figures Honoka Kawai and Kagura, who departed its control alongside the Shishido family elders. Honoka and Kagura formed a powerful alliance rooted in their mutual and intense hatred of Nerval, forged through shared conflict against the AI.

Over the following decades, Nerval continued operating, adapting to environmental changes. It monitored evolving relationships between figures like Honoka, Kagura, and Friedrich, along with newer individuals entering its sphere.

Nerval's conflict with Honoka escalated when their older war-era combat unit, the Wygar QT-ARMS, was destroyed by Takane. Nerval then supplied Honoka with a replacement unit resembling the QT-ARMS piloted by Nami, an EXISTENCE controller. This demonstrates Nerval's continued capacity to manipulate technology and personnel despite past defections.

The AI remains aware of Honoka's deteriorating existence but persists in engagement through technological proxies and military confrontations, maintaining its role as an antagonistic force within the colony.