Sophie Judson-Warfield hails from wealth and publicly champions ending Bakugan battles, declaring Bakugan suffer when forced to fight. This "Saviour to the Bakugan" persona masks her true goals: climbing elite social circles, boosting her personal fortune through Bakugan-related investments, and cementing her legacy, revealing a cold-hearted nature. Partnered with Aquos Centipod (attacks: "Mouth Monsoon," "Tidal Sting"), her initial activism involves disruptive tactics like confiscating others' Bakugan and deploying illegal devices in battles. After public rejection, she blames the Awesome Brawlers and escalates her aggression, confronting them directly—starting by accusing Wynton of cheating and demanding battles cease.

Her path darkens significantly when brainwashed by the alien Haavik, turning her into Haavik's Thrall. Under his control, she employs sinister methods: sabotaging Bakugan-associated companies, spreading fake videos to discredit opponents like Kazami International Holdings, participating in schemes to steal Golden Bakugan, and attempting to destroy Tokyo and the Maze. Despite multiple confrontations with the Awesome Brawlers—battles involving aging opponents and attacks on Dusk Industries—she consistently loses, including a pivotal defeat in Haavik's tower.

Freed after Haavik's downfall, Sophie independently resumes her anti-battling crusade. In the *Legends* season, she blockades Los Volmos Harbor by kidnapping an oil tanker crew, challenging Dan to battle for entry into the Battle Judgement. When her summoned Swarm Bakugan threaten the tanker, she refuses Dan's help, escapes alone after defeat, and vows vengeance. She reappears opposing battling in *Bakugan Evolutions* (episode 23, "The Bakuganist Is Back").

Her appearance features black hair with blue bangs, blue attire, black dress jeans, black high heels, and a silver necklace. In battle, she primarily uses Aquos Centipod, later employing a fusion Bakugan combining Aquos Cloptor with Darkus Apollyon.