The XF-3 is a fully enclosed powered exoskeleton that turns a single operator into something approaching a light armored vehicle. The operator climbs into the suit through a rear-mounted hatch, connects their BCI to the control interface, and gains access to a 2.8-meter armored chassis with hydraulic strength amplification that allows them to lift 800 kilograms, sprint at 45 km/h, and absorb small-arms fire without slowing. The suit carries an arm-mounted 20mm rotary cannon fed from a back-mounted ammunition drum and a shoulder-mounted grenade launcher with six rounds.

The experience of operating the XF-3 is, by all accounts, intoxicating and destructive to long-term mental health in roughly equal measure. The BCI interface provides full sensory feedback — the operator feels the suit as their own body, experiencing its strength and durability as personal attributes. Arcturus's neural engineering team designed the feedback loop to be deliberately euphoric during combat operations, producing a neurochemical response that operators describe as the most intense experience of their lives. The crash after disconnection is proportionally devastating. XF-3 addiction — the compulsive need to be inside the suit — is a recognized medical condition among Arcturus combat personnel.

The nickname 'Walking Coffin' has a dual meaning: it describes what the suit does to enemies, and what the suit does to operators. The BCI interface, over repeated connections, gradually erodes the operator's ability to perceive their unaugmented body as adequate. Long-term operators report feeling weak, slow, and fragile outside the suit — not because they are, but because the suit's sensory feedback has recalibrated their baseline expectations. Some operators eventually refuse to exit.