Shin is a talking wolf characterized by gray fur, black eyes, a yellow forehead marking, dark gray eyebrows, claws, a snout, and sharp teeth. He serves as the companion and animal guide to Aqulas, frequently communicating on Aqulas' behalf. Shin maintains a calm and collected demeanor but exhibits strong protectiveness, becoming rude when others threaten Aqulas. This vigilance extends to others generally. Shin debuted with Aqulas when they assisted Bull Borgnine against an attack by a B-Da Gang, forging a friendship where Bull calls Shin "Fido." Other characters, like Liena, often refer to him as "doggie." Following a period of corruption, Shin experiences lasting effects causing discomfort during B-Daman battles. This trauma manifests as difficulty loading B-DaBalls into Gatling Hades and dropping the B-Daman during matches. Shin expresses fear of recurring corruption and requests careful engagement during battles to avoid emotional pressure.