Upcast

An Upcast is a magical being that has been modified from it's original form. Then simplest example is a human who's been given a specific, defined magical power, but lacks normal magic capabilities. Upcasts were created extensively during the Mage Wars and also by Samuel Fate during the Long Night. While a borderline example since they can do regular magic, the Slayer Dragons are a type of Upcast having been modified by Draconic magic.