Myne Suphia serves as the alias for Malty S. Melromarc, first princess of Melromarc, concealing her royal identity during her time as an adventurer. She initially presents a facade of friendliness and support, notably joining Naofumi Iwatani's party when others refuse. This mask hides her true objective: exploiting him for personal gain. She manipulates Naofumi into buying expensive equipment he cannot afford, later stealing his money and chainmail to gift Motoyasu Kitamura, the Spear Hero. Her ultimate betrayal is falsely accusing Naofumi of sexual assault, fabricating a rape allegation that isolates him legally and socially, triggering his cynicism and unlocking his Wrath curse series. Profound narcissism, deceitfulness, and a complete absence of empathy define her personality. She habitually uses superficial charm and crocodile tears to manipulate, evidenced when she joins Motoyasu's party after framing Naofumi, stroking his ego to maintain control. Her manipulation extends to all interactions: she cheats in duels involving Naofumi, such as casting spells to hinder him during a dragon race for control of Riyute Village. She levies oppressive taxes on villages recovering from Waves, justifying her extravagance and misuse of state funds as being "for the sake of the world." Her ambition drives her to attempt regicide against her younger sister Melty, intending to frame Naofumi for the murder to secure the throne, even burning entire forests to locate them. After her false accusations are exposed during her trial, Queen Mirellia strips her of royal status and titles. As judicial punishment, Naofumi legally renames her "Bitch," with "Whore" and "Slut" as officially recognized alternatives for her adventurer alias. Implanted with a slave crest that inflicts pain when she lies, she continues to deceive reflexively despite the agony, demonstrating a pathological compulsion. Forced to accompany Motoyasu as part of her sentence, she later abandons him during the Spirit Tortoise crisis when his usefulness wanes, contributing to his psychological breakdown. She subsequently approaches Ren Amaki, slandering Motoyasu while feigning victimhood, only to betray and rob Ren as well. Her inability to read hostility or acknowledge responsibility remains consistent; she repeatedly begs those she wronged, including Naofumi and Motoyasu, for mercy when facing consequences, yet harbors only intensified resentment. Her background reveals early sadistic tendencies, deriving pleasure from others' suffering—a trait her mother attributes to being spoiled rotten by her father, King Aultcray. This fostered entitlement and avoidance of accountability. Her mother's attempt to reform her by sending her to study abroad in Faubrey failed, resulting only in her "graduation from virginity." Strategic incompetence is noted in her poor chess skills and repeated failures to detect betrayals against her, such as by the Church of Three Heroes or Rino, who exploited her inflated self-worth before fatally stabbing her. Her actions inadvertently catalyze the curse series of all four Cardinal Heroes: Naofumi's Wrath, Motoyasu's Lust, Ren's Greed and Gluttony, and Itsuki's Pride. Her later activities involve joining the interdimensional terrorist group Vanguard of the Waves, perpetuating destruction across worlds while seeking revenge against those she blames for her downfall. She remains unrepentant throughout, doubling down on manipulation, betrayal, and blame-shifting without meaningful development or redemption. Her psychological profile aligns with sociopathic traits: pathological selfishness, grandiose self-worth, absence of remorse, and chronic short-sightedness.