Varsus operates as a Cyber Police-assigned robotic assistant monitoring convicts repurposed as law enforcement officers. This wheeled unit primarily accompanies the convict Sengoku on missions, delivering directives, providing command updates, and enforcing compliance via reminders about the explosive collars worn by convicts. It issues time-limit warnings and detonation threats relayed from Chief Hasegawa.

Behavioral monitoring forms a core function, prompting Sengoku to adhere to legal protocols and avoid misconduct like on-duty drinking. These interventions frequently trigger friction, drawing profanity-laced insults from Sengoku. Varsus counters with literal corrections—such as dissecting phrases like "fuck off" by noting its inapplicability to non-biological entities.

During critical operations, like a compromised skyscraper's system breach, Varsus supplies real-time tactical data. It occasionally engages in philosophical discussions, including debates about systemic flaws originating from human creators, as observed during an elevator confinement with Sengoku. Its presence remains exclusively tied to Sengoku across all documented media, including original OVA episodes. The unit demonstrates no evolution in role, design, or functionality, persisting as a protocol-driven enforcer whose rigid logic creates comedic contrast against human emotion and profanity.