In Nusu animism, the number and nature of a person’s ‘soul attributes’ change during his or her lifetime and after death. Drawing on Michael Scott’s study of Arosi poly-ontology, this article situates animistic personhood in a plural socio-cosmic order. Living and dead, human and non-human, Nusu and non-Nusu occupy separate, communicating domains. Meaningful exchanges across boundaries require the metamorphosis of persons and ideas. Nusu animism, continuously engaged in an ‘algebra of souls’, understands the self in terms of its multiplicity, its latent and emerging aspects. Through the ethnography of two death rituals—one ‘real’ and one staged for visiting researchers—this article shows that animism is being hyper-reflexively reinvented by Nusu animists themselves.