Ninny Spangcole is a witch and Wing Bind protection agent, partnered with Noel Niihashi, in the dragon conservation organization of Reverse London. She possesses green eyes and blond hair styled in two long pigtails secured by red, spiked metal bands. Her standard attire includes a green suit worn open over a white undershirt, black shorts held by shoulder straps featuring a golden gemstone, and a red-and-black plaid cape fastened with a large red bow bearing the Conservation Rangers symbol. Her legs wear mismatched stockings: the left extends to her thigh with three white stripes, while the right is rolled down to accommodate a thigh holster for her Witch Kit. She completes the outfit with black boots adorned with gemstones at the ankles.

Ninny exhibits an abrasive, rude, and temperamental personality. She berates repairmen for gate reconstruction delays after instructing them to prioritize installing a large monitor for her advertisement. She insists Noel avoid calling her "Ninii-chan" due to their age difference and frequently criticizes Noel's fascination with Japanese culture. Ninny openly expresses disdain for commanding officer Billy Banx Jr., often yelling insults at him. Driven by ambition to join the elite Sabre Squad and defend London's streets, she prioritizes achievement points over monetary rewards for promotion. She prevents Noel from summoning Sabre reinforcements during a Dark Dragon confrontation to prove her combat capabilities. Ninny becomes enraged when Billy receives a Sabre promotion after they defeat Shelby, and fumes when Noel is featured as the Wing Bind Headliner in the Reverse London Press, believing her contributions were greater.

She shows reluctance toward unpaid extra duties like supervising Balgo Parks and his dragon Osushi unless offered overtime pay. During missions such as harvesting grapes from a dragon's nose in Ninebrook Pastures, she voices frustration with Reverse London's dragon protection policies, preferring Japan's approach of eliminating monsters. Ninny holds a cynical view of fairy tales for failing expectations and scorns those idolizing princesses, preferring to be the magic-wielder driving such stories. As the popular singer in Cecile Die Twice, she has little patience for intrusive fans, using magic flashes from her phone to temporarily blind and evade them. She remains indifferent to media distortions from outlets like "The Realist," accustomed to false narratives.

Despite her harsh exterior, Ninny demonstrates compassion in critical moments. After an attack by Dark Dragon Shelby leaves her injured near Balgo Parks, she immediately urges him to flee. She displays loyalty to fellow singer Macy Baljure, whom she considers mentally unstable and irritating. When Macy unknowingly commits a felony by revealing ownership of dragon Elly, Ninny protects her from consequences. During an escape from Bruno Bangnyfe, she ensures Macy's safety alongside Noel and Balgo.

Her operational duties involve responding to dragon-related threats across London and Reverse London. During one mission, she pursues Shelby despite warnings about multiple dragons, resulting in a broken arm when Shelby reveals his true Dark Dragon form. Balgo shields her from a subsequent attack, enabling Noel to destroy Shelby. Later, Ninny participates in containing Osushi's unexpected transformation and battles a disguised Dark Dragon, insisting on handling it without Sabre support to showcase her abilities. She accompanies Noel and Balgo to investigate an illegally-reared dragon in Reverse London's west district after an anonymous tip, motivated by quintuple pay despite initial reservations.