This paper combines ethnographic fieldwork and traditional African philosophy to examine the role of the Obasinjom masquerade’s witch hunting ritual performance in individual and community therapy among Bayang and Ejagham ethnicities of Southwest Cameroon. They are a crossborder Bantoid people living in both Southwest Cameroon and Southeastern Nigeria with common sociocultural and sociopolitical institutions including cult agencies (secret societies). Aside from sharing a common world view characterised by the entanglement between the material and immaterial realms, they further believe in reincarnation and see death as a transition from the material universe into the immaterial world of the ancestors. Accordingly, elders and traditional rulers are believed to be intermediaries between the worlds of the living and those of the dead. Like other African people, they have both a personalistic and naturalistic disease theory system and share a wide variety of ritual medicines for the diagnosis and treatment of diseases. Illnesses believed to be caused by personalistic agents-witchcraft are the domain of the Obasinjom cult agency-the god of medicine-which is physically represented by a speaking mask. The mask is believed to be omniscient and endowed with clairvoyance and supernatural powers. Through the dual processes of revelation and `remembrance’, Obasinjom connects the past, present and charts the future. This is done by using its supernatural powers to trace and unveil the mediating object and circumstances through which the malevolent spirit gained access to its victim. It is therefore involved in recreating the `biography’ (Kopytoft, 1986) of how the malevolent spirit gained access to its victim’s life essence. The Obasinjom mask is transformed through ritual performance from a banal into a ritual object thereby relating it to persons and events and attributing to it a biography and agency. This essay documents the specific role of the Obasinjom mask as overall controller over ritual medicine. The paper also examines the diffusion and subsequent appropriation of the Obasinjom cult agency by other Cameroonian ethnicities for ensuring community health and well-being because of its detective role in exposing witchcraft practices and criminal activities. Grounded in the African world view of health and personhood, the essay demonstrates that the Obasinjom cult agency’s performative ritual healing is a recreation of community sentiments among participants.