Eri, a young girl with bluish-white hair and crimson eyes, bears a small horn on her forehead that elongates when her Quirk activates. Born into the Shie Hassaikai yakuza clan, her childhood shattered when her latent ability, Rewind, manifested uncontrollably, erasing her father from existence. This tragedy drove her mother to abandon her, leaving Eri under the care of her grandfather, the group’s ailing leader. His decline ushered in Kai Chisaki (Overhaul), who seized control and imprisoned her, harvesting her blood through relentless experiments to craft Quirk-destroying bullets. Convinced her power could dismantle society’s dependence on Quirks, he subjected her to years of torment. Trauma and guilt molded Eri into a timid, withdrawn child, convinced her mere presence brought catastrophe. Repeated escape attempts failed until Izuku Midoriya and Mirio Togata intervened during a work-study mission. Though she initially surrendered to Overhaul to shield her rescuers, a decisive raid liberated her from the compound. The aftermath left her emotionally fractured, her capacity for joy buried under layers of isolation and manipulation. Under U.A. High School’s guardianship, Eri’s healing commenced. A pivotal moment arrived during the U.A. School Festival, where a musical performance by Class 1-A sparked her first unguarded smile—a fleeting yet profound breakthrough. Guided by Eraser Head, she began mastering Rewind, a Quirk capable of reversing time within living organisms, mending wounds, restoring erased abilities, or erasing lives entirely. The horn on her forehead functions as a reservoir, stockpiling energy over time. Fearful of her power’s destructive edge, she gradually embraced its healing potential after Izuku reframed it as a lifeline, not a curse. Her growth crystallized when she restored Mirio Togata’s Permeation Quirk ahead of the Paranormal Liberation War, risking her own safety to aid others. By the Final War, she contributed a fragment of her horn to bolster Shota Aizawa’s efforts against Quirk-driven threats. Post-conflict, her regenerated horn mirrored her renewed spirit as she embraced ordinary life—attending middle school, exploring music, and nurturing fragile hope. Eri’s journey, interwoven with bonds to heroes like Izuku and Mirio, wove themes of endurance and redemption. Her story probed the moral ambiguities of Quirk application while affirming compassion’s transformative force in mending fractured lives.