Major Mary founded and commands the Twin Star Troupe, fiercely viewing Volcott O'Hue and his Angel Troupe as professional rivals. This rivalry drives her to employ cunning, often unethical tactics, including sabotage, to secure her troupe's dominance over the Angels. She once planted a bomb disguised as a treasure chest to disrupt an Angel Troupe mission and later wielded her "Wonbat"—a baseball bat-like weapon featuring a dog head—against Volcott in a physical clash. Intensely ambitious, Mary perceives the Angel Troupe's assignment to Volcott as a direct threat to her own promotion, fueling visible frustration and hostility. Her personality features exaggerated reactions: she hallucinates cheerleaders for self-encouragement under stress and suffers mental breakdowns over professional setbacks. She also fixates intensely on trivial matters, reacting with disproportionate anger to insults about Volcott's mustache. While primarily antagonistic, she occasionally engages in formal competitive challenges, confronting the Angels in tactical simulations or direct skirmishes. Her interactions frequently involve physical comedy, such as transforming into a giant during battles or enduring misfortunes like collisions with her own subordinates.