The What has come Before (that comes before) at the start of TTT sparked an idea. It emphasizes the "nothing" that the Mandate finds.
This made me think that Achamian is something of a Prince of Nothing, himself.
As is Cnaiur, when his Utemot/People/Ground/Identity are destroyed by the machinations of the Dunyain, he is no longer of the People, he stands apart and mimics being of the People, even though he is chieftan of the Utemot, he is not of the Utemot, he is more or less a Prince of Nothing.
And of course the literal text that tells us Kellhus is a Prince of Nothing.