In the process of transmission of tantric Buddhism from one culture to another, tantric deities often undergo multivariant configurations as the lineages of their transmissions grow in numbers, and as the legends of their origins, religious and social roles, and ritual practices expand. This lecture centers on one such deity, a fierce deity known in Mongolian and Tibetan Buddhism under the names Jamsran and Lcam sring, or as Begtse Brother-and-Sister. Jamsran embodies two classes of deities—the Buddhist war deities and Dharma Protectors—whose violent actions and fierce nature are directed toward the mundane and religious pragmatic ends. Two identities of Jamsran—that of an emanation of Amitābha and the other of a fierce yakṣa—are possible to coexist due to his lack of the reified ontological basis, which makes him functionally and culturally adaptable.