USApyon manifests as a Yo-kai clad in a yellow rabbit-themed spacesuit featuring hood ears, equipped with an orange carrot-shaped "Bunny Blaster" ray gun, a blue jet pack, and a wispy purple flame-like tail. His true form, concealed beneath the suit, resembles an otter with white-tipped extremities and a red star-patterned scarf. Originally a wild otter named Danny (or Chibi), he endured neglect in a rabbit pen before adoption by scientist Dr. Hughly for a space program. A panicked reaction during a rocket engine test triggered a fatal explosion, resulting in his rebirth as a Yo-kai. He harbors guilt over inadvertently causing Dr. Hughly's resignation. Personality-wise, USApyon is serious, ambitious, and highly intelligent with rocket science expertise. He possesses a notoriously short temper, easily provoked into "Invader Mode" (or "Vader Mode"), where a black visor descends, smoke fills his helmet, and his eyes glow red. In this state, he fires indiscriminate red laser beams, often targeting annoyances like his human partner, Hailey Anne. Despite this irritability, he demonstrates loyalty and care for close bonds, such as with Dr. Hughly, and suffers monophobia rooted in pre-Yo-kai isolation. His capabilities include firing electric blue beams with the Bunny Blaster and transforming into Invader Mode via helmet buttons. At peak rage, he activates "Emperor Mode," gaining red armor, a teal cape, enhanced strength, flight, and a more powerful pink laser beam. He utilizes a Yo-kai Pad to gather information on other Yo-kai. Gameplay mechanics note increased combat effectiveness at low health; items like the Machonyan Soul or Imperial Chip optimize his mode transformations. The Tofupyon variant features a self-resurrection ability synergistic with Emperor Mode. USApyon employs specialized gear altering elemental attributes and Soultimate moves: - Football Gear (Fire/Lightning attribute, Soultimate: Quarterback Sack) - Racing Gear (Lightning/Wind attribute, Soultimate: Road Rage) - Scuba Gear (Water attribute, Soultimate: Scuba Splash) - GI Gear (Earth attribute, Soultimate: Air Support) His story begins by tricking Hailey Anne into obtaining a Yo-kai Watch U prototype, revealing his Yo-kai nature (not alien) and enlisting her aid to locate Dr. Hughly. Reuniting with the hospitalized professor, they build a model rocket to reignite his space passion, evolving into the "InaUSA Detective Agency" investigating Yo-kai mysteries in Sparkopolis. Key relationships feature a fraught partnership with Hailey Anne, whom he frequently targets yet deeply cares for; reverence for Dr. Hughly; and camaraderie with fellow "Merican" Yo-kai like Tomnyan—though even Tomnyan faces laser attacks. He also interacts with Nate Adams, Whisper, and Jibanyan, often staying at Nate's house during conflicts with Hailey Anne. Recurring narrative elements include an obsession with rocket models—reacting violently to the destruction of his "4 rocket"—and detective work facing challenges like the agency's temporary shutdown after the Phantom Thief Kopin incident.