Operating directly under King Drasil (Yggdrasil), the Mysterious Man, alias Dark Gennai, serves as a primary antagonist executing a plan to prevent human-Digimon coexistence. His core motivation stems from a belief that humans enslave Digimon and disrupt their natural rebirth cycle, making humanity's eradication essential. He possesses shapeshifting abilities, assuming identities like the Digimon Emperor and the trusted ally Gennai. The discovery of the real Gennai imprisoned alongside the missing *02* DigiDestined confirms him as a distinct impersonator. His appearance consistently features short brown hair tied in a ponytail, pale blue eyes, and black robes with a purple turtleneck. His actions drive the central conflict. He orchestrates infections turning Digimon hostile, specifically targeting Meicoomon for her connection to Apocalymon's data. He manipulates events to induce her fury, believing anger can force Digivolution—abducting her, provoking her into Vicious Mode, and strangling her human partner Meiko Mochizuki to trigger evolution into Meicrackmon Vicious Mode. He oversees the Digital World reboot, severing DigiDestined-partner bonds per King Drasil's plan. He exhibits a cruel, sadistic personality, openly reveling in others' suffering—laughing at Meiko's despair and expressing enjoyment during Taichi Kamiya's apparent death. He reactivates defeated villains like Machinedramon (Mugendramon) and MetalSeadramon to attack the DigiDestined, though they are defeated. He engineers the fusion of Raguelmon and Ophanimon Falldown Mode into Ordinemon, intending it to destroy the human world. After falling underground with Taichi and Daigo Nishijima, he appears in the lab housing the comatose *02* DigiDestined and real Gennai. He deactivates the *02* group's life support, forcing a choice leading to Daigo's sacrificial death and the lab's destruction. Following Ordinemon's defeat by Omnimon Merciful Mode, he retrieves an Apocalymon data fragment from Meicoomon's remains. Escaping through a dimensional distortion, he declares intent to continue his plans using Demon or Diaboromon, referencing an inherent desire to "play" within everyone.