Katsuya Serizawa, a formidable esper haunted by childhood bullying and destructive psychic outbursts, retreated into solitary confinement for 15 years. Adrift without guidance, he was recruited by Claw’s Toichiro Suzuki, who granted stability through a power-regulating umbrella and a veneer of belonging. Serizawa clung to Claw’s Ultimate 5 as a surrogate family, rationalizing their crimes while craving normalcy and connection. Following Claw’s collapse, Reigen Arataka of Spirits and Such Consultation Office sheared Serizawa’s unkempt hair, marking his rebirth. Tentative and reliant on the umbrella to contain his abilities, he slowly blossomed through night school studies, collaborative exorcisms, and newfound camaraderie. His progress culminated in discarding the umbrella entirely, channeling psychic energy through raw focus. During the Divine Tree crisis, Serizawa purged yokai infestations with disciplined precision. When Mob’s catastrophic energy vortex erupted, he shielded Reigen valiantly before tactically withdrawing as his stamina fractured—a testament to steadfast loyalty and residual vulnerabilities. Promoted to Deputy Director in the REIGEN spin-off, Serizawa guided protégé Tome Kurata through paranormal cases. He dismantled illusory threats during a hostage rescue and risked his safety to extract a curse from Tome, despite temporary collapse. His gentle rapport with Sho Suzuki and protective mentorship revealed a nurturing core. Once socially stunted and guileless, Serizawa matured into a deliberate, compassionate figure who initially sequestered himself to safeguard others. Reigen’s influence and peer bonds nurtured his self-assurance, refining his communication and identity. Leisure hours found him studying, curating Western fashion digitally, constructing meticulous plastic models, and savoring ambient melodies or office-life cinema. A parallel dimension crisis during Spirits and Such’s inaugural trip tested the team. While Reigen faltered, Serizawa deciphered spatial anomalies through calm analysis, orchestrating their escape with methodical teamwork. Physically distinctive with tousled dark curls, a towering frame, and a crackling violet aura, Serizawa swapped Claw’s orange hanten for a crisp blue suit post-redemption. His mastery spans psychokinetic force, technopathic manipulation, and spirit purification, transitioning from umbrella-aided restraint to unfiltered command. Key bonds include disillusionment with Toichiro’s manipulation, Reigen’s role in fostering autonomy, and Mob’s quiet impact as a peer embodying ethical power use. Serizawa’s journey mirrors Mob’s battles with ability and self-doubt, both navigating redemption and the fragile path to societal acceptance.