An Agent Ex — a heavily-cybered covert operations specialist who has formally cut ties with Matsumoto to work in the shadows with Yossarian's crew. Lupin has restless eyes, an ambiguous face, artificial skin, and an augmented, highly flexible build honed for infiltration; he keeps his hair short and dresses for utility rather than style.
Lupin's original training was as a Matsumoto "Cleaner" — spy and assassin work — before he left the corporation over a conflict of loyalty. His cyberware reflects that background: heavily replaced synthetic nerves give him near-superhuman reaction speed, and implanted skillwires make him an instant expert in martial arts, breaking and entering, vehicle gunnery, and operating in the hostile environment outside the dome. He carries two cyberarms, both augmented for strength — one housing a concealed holdout firearm loaded with gel rounds, the other fitted with a monofilament "nanowhip" capable of shredding armor and flesh alike — beneath a layer of subdermal plating. Over the course of the campaign, both arms were destroyed and rebuilt more than once, a running toll of just how much punishment Lupin is willing to absorb for the team.
Lupin's decision to leave Matsumoto traces back to his friend Jace Nakata, a tech smuggler who fell into serious debt with the Yakuza after losing a shipment of augmented skill chips meant for them. When his loyalty to Jace came into conflict with his corporate position, Lupin chose Jace and walked away from Matsumoto, though he still keeps a line open to his old team leader, Tonya Reade, when he needs a favor. He was the one who stole and sold encrypted data on the crime boss known as The Zephyr, gutting her criminal operation in the process. Razor is the one who introduced Lupin to Yossarian's crew, recognizing shared goals against the Yakuza.
In the field, Lupin has proven to be the team's most reliably devastating close-quarters fighter and infiltrator: he smuggled himself into a heavily guarded transport bay inside a shipping crate, tore a security commander's arm off with his nanowhip during the Irkmine heist (losing his own arm to a stray whip in the exchange), infiltrated Nordic Financial Holdings' offices through a drone-maintenance slot, tore a vault door bodily off its frame, and caught a live grenade meant for his teammates and threw it back into Wolf King's face. During the Daedalus' Mistress extraction, he suited up in a squirrel vac-suit for a solo spacewalk between shuttle bays and physically wrestled a rival cyberninja to his death in mid-air.
Despite his brutal effectiveness, Lupin quietly sends part of every payday to his sister, Anneke, a maintenance worker on Little IO who left Earth for the Jupiter Corp colonies in 2227. His small collection of old books — including The Art of War and, incongruously, The Zombie Survival Guide — is one of the only personal items he keeps at the team's safehouse.