Tengen Uzui emerged from a shinobi clan that subjected him and his eight siblings to brutal training regimes from childhood. Three siblings perished before reaching ten, while the remaining six were pitted against each other in masked combat—a practice that led Tengen to inadvertently kill two brothers. By fifteen, only he and a younger brother remained. Their father enforced merciless doctrines, demanding absolute reverence for strength and reducing wives to reproductive tools. Repulsed by these values and his brother’s compliance, Tengen fled the clan with three wives—Hinatsuru, Makio, and Suma—instilling in them a sense of identity beyond their clan’s dehumanizing dictates. As a member of the Demon Slayer Corps, Tengen ascended to the rank of Sound Hashira, wielding twin Nichirin blades modified for detonation and honing echolocation techniques. His physical prowess placed him second in raw strength among the Hashira, augmented by remarkable speed and agility. During the Entertainment District mission, he pursued the disappearances of his wives, clashing with Upper Rank Six demons Daki and Gyutaro. Despite sustaining lethal poisoning, losing his left hand and eye, he helped defeat the duo alongside Tanjiro Kamado, Zenitsu Agatsuma, and Inosuke Hashibira. Nezuko Kamado’s Blood Demon Art counteracted the poison, sparing his life. Incapacitated by injuries, Tengen retired but contributed to the Hashira Training Arc by supervising stamina exercises. His typically stern attitude eased around Tanjiro, whose progress he openly recognized. During the Infinity Castle conflict, he protected the Ubuyashiki family and observed Nezuko’s unprecedented resistance to sunlight. Surviving the Corps’ disbandment, he later married—fathering a child of unspecified parentage—and forged a friendship with Giyu Tomioka. His lineage persisted through a descendant mirroring his appearance and temperament. Tengen balanced flamboyance with practicality, flaunting audacious confidence while prioritizing his wives’ well-being and comrades’ survival. His traumatic upbringing forged resilience, driving him to reject clan brutality in favor of loyalty and compassion. Rather than succumb to stoicism, he embraced exuberance, channeling it into a combat style blending acrobatics and calculated theatrics. His evolution from self-aggrandizement to cooperative leadership marked his legacy. Surviving peers claimed by battle or the Demon Slayer Mark’s curse, Tengen’s endurance and mentorship endured. Relationships with his wives and Tanjiro exemplified themes of redemption, reshaping purpose beyond rigid duty.