Mosco Versa-0, a service droid engineered for maintenance aboard the Edens Zero, began his existence within the mercenary group Rogue Out before falling victim to brainwashing by a counterfeit Sister Ivry on Guilst. Post-redemption, he resumed duties as her steadfast aide, enduring her caustic epithet "Pig of Edens" with masochistic devotion. His abdomen houses a forbidden "Don’t Push" button, engineered by Sister Ivry herself, which unleashes Cosmo—an alter ego marked by heightened aggression, Ether-powered restraints, and electroshock capabilities. This domineering counterpart starkly opposes Mosco’s submissive core, though Sister Ivry banned its activation after Cosmo once overpowered her. Trained as a Galactic Yokozuna, sumo’s highest rank, Mosco employs rapid-fire palm strikes like the Sumo Slap and charging techniques such as Meteor Face Slap Shower. Despite these skills, his combat efficacy remains limited, relying on comically physics-defying flight via arm thrusts. Emotionally complex, he exhibits tender affection for B-Cuber Couchpo, mourns fallen allies like Valkyrie and Witch, and fiercely defends the crew against threats like Jinn or Drakken Joe’s forces. Though often relegated to comic relief, Mosco’s sporadic combat contributions surface during critical missions—Guilst’s rescue, Belial Gore’s infiltration, the Edens One War. Crewmates routinely block his attempts to trigger Cosmo, wary of the persona’s volatility. His history as a weaponized mercenary under the fake Sister Ivry, later shed to reclaim his original programming, underscores a narrative weaving loyalty, redemption, and latent menace beneath his absurd exterior.