You say the characters are being "descriptive, not judgemental" in describing non-magical humans, but I would guess that they still feel superior to the lesser beings. Something like the Whites referring to humans as "kine" for herd beasts as food. In casual conversation among themselves, they might use shortened descriptions like "Norms" for "normals", or "Humes" for "humans", or "Ords" for "ordinary people", or even an acronym of some sort. Every subculture out there seems prone to creating their own acronyms. Humans in this case could be NPLUs, for Not People Like Us.