Chiefson operates as an executive in the Phoenix Group, a clandestine organization dedicated to capturing immortals and stealing their secrets for worldwide control. He supervises missions targeting figures such as Akira Inugami, who wields wolf-like immortality. Chiefson personally engages in the abduction of Akiko Aoshika, a high school teacher tied to Inugami, and approves her sedation with "Narcotic 800" to convert her into pliant bait. This strategy intends to ensnare Inugami. His conduct supports the Phoenix Group's primary aims of eradicating immortal threats and weaponizing their powers.