Generator Rex

Five years prior to the series, a massive explosion released high concentrations of nanites into the atmosphere, infecting every living thing on Earth. These nanites may randomly activate inside their hosts, mutating the subject into a monster known as an E.V.O. (or "Exponentially Variegated Organism") - usually a mindless creature that attacks everything around it, though some E.V.O.s retain human-level intelligence. To combat the E.V.O. threat, an international organization known as Providence was created.

Rex is an amnesiac teenager who is not only infected with nanites like everyone else, but is an E.V.O. Unlike most E.V.O.s, however, he is not deformed in any way; unlike all other E.V.O.s, he is able to control his nanites, allowing him to manifest a variety of powers and even cure others of their mutations. Working for Providence under Agent Six, Rex uses his unique abilities to help stop E.V.O.s as they appear. Working against Providence is Van Kleiss, a sinister E.V.O. with connections not only to the Event which released the nanites, but to Rex himself.