Triads

 Welsh triads, a historical form found in Medieval manuscripts where folkloric and mythologic tidbits are presented in groupings of three seem a compact way of delivering some light setting info. 

Playing with the form, I came up with a couple related to the setting I posted about here. 

Three terrible spectres of the Realm:
Pendhol,who seeks his lost crown and lost head in the hills of Hern,
And Llaithwyn, Lady of the Night Mists, who the wise give courtesy but only fools embrace,
And Black Gawl, the hound loosed by the Beast from the Outer Dark to herald the doom of Men.

Three cunning folk of the Realm:
Morgna, witch and shape-changer, whose hut wanders the Marshes of Morva,
Wyrthegern the Mad, who lives in the wild and speaks in riddles,
And the Wizard Midhryn of Many Names, who was judged most cunning of all.