The Guardian Robotic, designated as the Police Mech Unit, originated as a riot suppression apparatus. An unexplained global amnesia event eradicated human memories and cognition, causing its operator's demise and rendering the unit pilotless. Its autonomous autopilot protocol engaged, sustaining operations independently.

Fitted with thermographic targeting and GPS tracking systems, it identifies humans regressed to feral states as violators of pre-amnesiac statutes and executes assaults. The unit exhibits relentless operational persistence, including self-repair functions enabling prolonged pursuits across vast distances.

After an initial confrontation in San Francisco resulted in its temporary disablement, the unit pursued a primary target relentlessly across the American continent. This chase traversed multiple regions, including Washington D.C., culminating in a final engagement in New York City. There, it was destroyed after being forced into a terminal descent from a skyscraper.

Its mechanical design, conceptualized by Yoshitaka Amano, displays a distinctive visual profile aligned with its riot-control inception.