Are Guardians of Ancient Kings and the Ancient Kings souls ascended by The Light?

Seriously, what are they? There's literally zero lore on who they are. There is one instance where they're called 'Avenging Angels', but no one ever acknowledges their connection to The Light (among other angelic themed magic for Light-wielders). If they are angels unrelated to the kyrian, are the Naaru like the so-called "Biblically-accurate" angels?