Teitoku Kakine holds the position of Academy City’s second-ranked Level 5 esper, wielding the enigmatic ability to generate and control Dark Matter—an anomalous substance that violates known physical laws. This power enables him to produce 25,000 distinct energy forms and weaponize innocuous environmental elements like sunlight or air. Dark Matter operates on quantum principles, bypassing traditional defenses to strike targets at a fundamental level. As founder of the clandestine group SCHOOL, Kakine positions himself against rivals Accelerator and Mugino Shizuri, fueled by an obsession to dethrone Accelerator as the city’s paramount esper and claim his role in its secretive projects. Their confrontation ends with Accelerator annihilating Kakine’s original body, but Academy City resurrects him using stored biological samples and Dark Matter. This rebirth traps his consciousness within the substance itself, forging an immortal form that regenerates from near-total disintegration. Kakine embodies arrogance, tactical brilliance, and merciless ambition, cloaked beneath a veneer of affability. He strategically avoids directly endangering civilians yet refuses to shield those who cross his path. Childhood tragedies linger in his past, subtly influencing his ruthless drive for supremacy. Post-resurrection, his powers escalate: he crafts perfect human replicas, rewrites biology via cellular Dark Matter manipulation, and envisions supplanting humanity with his creations. His postcognition skill reconstructs past events by interpreting residual Dark Matter signatures. However, his revival fractures his identity. Beetle 05—a splintered persona prioritizing restraint—usurps his role, safeguarding Fremea Seivelun while deliberately curbing self-replication to contain the original Kakine’s influence. The true Kakine endures as a dispersed consciousness within the Dark Matter network, scheming to reclaim dominance. His pursuits span vengeful clashes with Accelerator, interventions in events like the Fräulein Kreutune incident, and temporary resurrections orchestrated by groups like Gremlin. Though Beetle 05 subdues him, remnants of his will linger across the Dark Matter matrix, preserving his status as an enduring, dormant hazard capable of resurgence under precise conditions.