Kakine Teitoku, Academy City's second-ranked Level 5 esper, wields the power to create and control "Dark Matter," an exotic substance governed solely by his own rules, defying natural laws. This ability enables diverse applications: projecting energy, manipulating environments, transmuting matter, twisting harmless phenomena like sunlight into deadly threats, and generating approximately 25,000 distinct energy forms. Common manifestations include six wings spanning tens of meters for flight and combat, light-diffraction lasers, explosive blasts, and crushing pressure fields. A past tragedy, implied to mirror Accelerator's, drove Kakine to Academy City's dark side. He founded and led the clandestine organization SCHOOL, aiming to force negotiations with the city's overseer, Aleister Crowley, whom he resented for treating him as a disposable "spare plan." This fueled his bitter rivalry with Accelerator, whom he envied for direct access to Aleister. Kakine saw defeating Accelerator as essential to claiming the top rank and achieving his goals. Kakine exhibits ruthlessness, arrogance, and cold pragmatism. He tortures or eliminates adversaries without hesitation, exemplified by his near-fatal assault on Uiharu Kazari to extract information on Last Order. However, he occasionally shows restraint, such as sparing Takitsubo Rikou upon recognizing her imminent demise from ability overuse. He avoids involving bystanders but offers no protection if they interfere. Underlying his aggression are insecurities; he openly acknowledges his own vileness and inability to protect others, hinting at a desire to reform Academy City to prevent tragedies like his childhood friend's death. Sarcasm and mockery punctuate his speech, often praising foes while demeaning them. During the Battle Royale arc, he infiltrated the Elementary Particle Engineering Laboratory to steal the "Tweezers," a microscopic manipulation device he optimized for combat. He clashed with ITEM, interrogated and betrayed Frenda Seivelun, and battled Mugino Shizuri—defeating her but failing to ensure her death. His confrontation with Accelerator culminated in his physical destruction. Academy City preserved his organs to mass-produce Dark Matter for military applications. While confined, his consciousness persisted within the Dark Matter network, studying Accelerator's abilities and refining his own power. He later revived by reconstructing his body entirely from Dark Matter, shedding biological limitations like aging, respiration, and sustenance. This granted high-speed regeneration, nigh-immortality (surviving as long as any Dark Matter particle exists), and expanded abilities like postcognition (recreating past events via environmental saturation), shapeshifting, and creating autonomous constructs. Seeking vengeance against Accelerator and handling the Fräulein Kreutune incident, he fought both Accelerator and Mugino simultaneously. Their efforts proved futile until Takitsubo Rikou's AIM Stalker ability disrupted his control, enabling Beetle 05—a benevolent fragment of his personality—to overwrite his network. Beetle 05 assumed the "Kakine Teitoku" identity as a heroic urban legend guarding Fremea Seivelun. The original consciousness endured as a latent entity within the Dark Matter, occasionally reemerging through external manipulation, such as Gremlin's use of his preserved organs. His post-revival physiology eliminated conventional weaknesses, rendering him immune to soul-based attacks due to his body being inorganic matter imprinted with data rather than a living being with a soul. The network's distributed nature allows simultaneous perception and action across all Dark Matter, though it remains vulnerable to interference from other Dark Matter users or specialized abilities like AIM Stalker.