In some ReBoot fanfic, there are specific kinds of Virus, based on powers and temperament. Megabyte is a Control Virus: he has powers specialized for brainwashing and seizing control, and corresponding megalomania. Hexadecimal is a Chaos Virus: her powers are vast, diverse, and unpredictable; her moods and thoughts are mercurial, but she helps as much as she harms. I don't like the idea of Doug being a User (judging by what little we learn about them, Users are everything Doug hates about Celestials), but I think it might be appropriate for Doug to look to Mainframe and its residents like a much weaker (and correspondingly saner) Chaos Virus. (I said "look", and not "Doug is a Virus", because my assumption is that Doug's person is invariant in transit: he can't be transformed by a Gate. On the other hand, a biological being doesn't fit into ReBoot's world very well, so Systems have to treat him as if he were a digital entity.)
On the other hand, if Doug isn't a User, there isn't really any reason why he shouldn't be treated as a Guardian himself. Bob (Guardian 452) merged with Glitch by giving it the instruction "Download". Doug and his Keytool were never separate, though he still needs to instruct his Keytool powers.
On the gripping hand, I'm not the one writing it, am I?
On the other hand, if Doug isn't a User, there isn't really any reason why he shouldn't be treated as a Guardian himself. Bob (Guardian 452) merged with Glitch by giving it the instruction "Download". Doug and his Keytool were never separate, though he still needs to instruct his Keytool powers.
On the gripping hand, I'm not the one writing it, am I?