Emerging from the corpse of an ogre, the character bears a human visage, his lineage obscured by mortal form. In place of brutish ogre features, he wields Onikirimaru—a sentient blade that defines his identity and purpose. His genesis intertwines with the demon Shutten Douji, whose essence he absorbed after emerging from a nun consumed by the creature. This origin reframes him as a divine entity bound to safeguard humanity, contradicting prior tales of pure ogre blood and weaving celestial purpose into his demonic roots.

Consumed by the conviction that eradicating every ogre will grant him humanity, he wanders Japan in relentless pursuit. His crusade, fueled by a longing for a name and ordinary life, persists even as he uncovers the futility of his mission—ogres endlessly reborn from human vice. This revelation casts his quest as tragedy, his awareness of its impossibility sharpened by encounters that blur the boundaries between human and ogre, hunter and hunted.

A prequel set in the Sengoku era deepens his lore, detailing clashes with figures like Suzuka Gozen, a demon who chose humanity after loving a mortal. Their rivalry juxtaposes his bitterness toward humans—born from their failure to protect his mother—against her capacity for empathy, suggesting dormant potential for his own transformation. Centuries pass without altering his ageless appearance, a visual testament to his suspended state between realms.

Onikirimaru, inseparable from his soul, cannot wound him, its edge lethally honed against ogre flesh yet mirroring his divided self. Though distant, flickers of compassion emerge—shielding the abused, subtle acts betraying a conflict between icy duty and residual humanity. These contradictions cement him as a tragic wanderer, forever torn between destiny’s chains and the fragile hope of transcendence.