Dr. Viktor (last name unknown) is the subpotentate for the United Russian States. He is only named once, in The Indwelling and identified as a doctor by Leon Fortunato.

Since a conspiracy to use the ten subpotentates to kill Peter Mathews involve asking subpotentate Od Gustav to sign the death certificate as he is a physician, it is possible that Viktor is a PhD holder in some scientific or humanistic discipline, rather than a medical doctor.