If they happen to be part of the Kingsglaive, they will be granted use of magic through their oath.

[Ignis keeps pace without complaint. It isn't too difficult, when conditions far more adversarial have been traversed through with a much quicker step before now.]

The magic used by Lucis' royal line, and the Oracle, are rooted in blessings from the Astrals. Our Gods. These blessings date back to the time of the first kings of Lucis.