Light or Dark, nobles or commoners, don't be fooled by labels. People from the empire are all just as cut-throat as each other...
The character are ordered according to their social status (high nobility, low nobility, commoners) and political affiliation (Light, Dark, other). They are also designated as POV character, important secondary character, minor secondary character, and background character (dead characters or characters just mentioned).
The high nobility, the most arrogant and entitled of them all...
Characters whose House rules an Estate.
The rulers of the Light faction. The 'good guys' caring for the poor and the oppressed, all wishing to outlaw dangerous magic for the good of the empire. All lies and propaganda of course.