Kōran Mori is the primary antagonist of the series. He is an immensely wealthy man whose main motivation is the attainment of eternal life, which he believes he can secure through the healing abilities of Yanagi Sakoshita. He is the husband of Tsukino Mori and the adoptive father of Kurei. His personality is characterized by extreme sadism, a thirst for power, and a profound lack of empathy. His goals are driven entirely by selfish desires for luxury and immortality. Mori’s role in the story is to act as the force behind the major conflicts. He is responsible for Kurei's tragic upbringing, raising him to suppress all emotions and become a perfect tool. He orchestrates the kidnapping efforts targeting Yanagi and ultimately sponsors the Killer's Tournament to secure her for his experiments. His key relationships are built on manipulation and abuse. To control his adoptive son Kurei, he holds his wife Tsukino hostage with a bomb implanted in her body. When Kurei displays emotion for a girl named Kurenai, Mori kills her using a similar bomb, demonstrating his complete lack of mercy and his absolute desire for control. His obsession with Yanagi puts him in direct opposition to Recca Hanabishi and his allies. Mori himself undergoes little personal change; he remains a consistently cruel and ambitious villain throughout the narrative. Nevertheless, his actions are the catalyst for the growth of other characters, especially Kurei, who eventually rebels against his control. Mori privately fears the immense power Kurei awakens but continues to exploit him as a weapon and shield. In terms of abilities, Mori possesses tremendous physical strength and speed. His body has an advanced regenerative capability, allowing him to survive dismemberment and regenerate lost limbs. He can manipulate his own body parts, extending them or forming sharp spikes. If a large enough piece of his body is separated, it can grow into an independent, monstrous replica of himself. He can also unleash powerful destructive energy blasts from his mouth and replenish his energy by consuming human flesh.