Marionettista, known as the Puppeteer, works for Haijima Industries' Ability Development Laboratory. Her role involves guiding children who have newly awakened pyrokinetic abilities. She utilizes specialized mechanical puppets called Dominion to create a supportive environment for their adjustment and training. Outwardly cheerful and nurturing, she presents herself as a "good big sister" to foster trust with the children under her care. Her appearance features lengthy eyelashes, light pupils, and dark hair swept into a ponytail. She typically wears a loose white shirt with a large frilly collar, dark trousers, shoes, and prominently highlights an angel-themed belt buckle. The Dominion puppets she controls are smaller than children but possess a robust mechanical design. Despite her friendly demeanor, Marionettista harbors a manipulative and condescending nature. She views both people and machines as predictable tools to be controlled, rationalizing that children "are meant to be used by adults." This perspective allows her to remain indifferent to their mistreatment by Haijima Industries despite her claims of caring. When provoked, she reveals a sinister side, becoming internally focused on brutal retaliation against those who anger her. A Third Generation pyrokinetic, Marionettista manipulates Dominion units through thin wires, using her own thermal energy as their power source. These puppets exhibit exceptional strength, capable of flipping vehicles and withstanding attacks from heavy weaponry. Their signature offensive capability, "Gas Blaster," involves firing potent flames from tailpipe-like structures. A specialized variant, the Dominion of Punishment, features claws sharp enough to slice through concrete and insulation against electrical damage. Her abilities also include projecting flames from her feet to slow aerial descents and possessing advanced mechanical expertise to build, operate, and analyze her equipment during combat. During the Haijima Industries arc, Marionettista was assigned to the laboratory to alleviate children's fears of Yūichirō Kurono. When Special Fire Force Company 8 infiltrated, she deployed her Dominion to attack their vehicle, causing severe damage. She engaged Maki Oze and Vulcan Joseph in combat, initially overpowering them. After Maki destroyed her primary Dominion unit, Marionettista summoned a swarm of replacements, only for them to be abruptly annihilated by Haumea of the White-Clad. Enraged by Haumea's interference and attitude, Marionettista redirected her aggression, pursuing the vulnerable Haumea after Vulcan temporarily neutralized her powers.