O5-3 "The Kid"

Unknown age. Unknown gender. Unknown ethnicity. Very little is known about the actual nature of O5-3. Often described by sources as not being human at all, and instead being an artificial intelligence designed to create other artificial intelligences. He/she has not ever appeared physically outside of Overwatch Command, instead appearing through avatars on screens, and speaking with a digitally constructed voice. The single image a source was able to find of O5-3 is of a very young Korean child in traditional ██████ apparel, which is unsupported by any other claims about the Overseer.

He/she is supposedly the direct report for █████ █████, the head of the Foundation's Recordkeeping and Information Security Administration, having seized that authority from ███ █████████ when those records became digital.

Notably, Foundation AIC units (such as the Alexandra and Thorn units) are incapable of discussing O5-3, despite evidence that information about him accumulates in their databanks as they learn over time.