This paper discusses syncretic agency in social mixed reality artworks that bridge digital and physical representations of identity. It proposes that mixed reality data transfer can constitute a "reterritorializing" effect that creates a syncretic post-biological digital identity for the user. Recent examples from computer science and artistic practice are summarized to illustrate deterritorialization and reterritorialization effects. One example discussed is the artist Paul Sermon's work that explores concepts of presence and performance by blurring the boundary between online and offline identities through mixed reality techniques. Another example is the mixed reality artwork "Terra(socio)sonica" that translates physical movements into soundscapes in both the physical and virtual realms.