Prescia Demorri is the Grand Shaper of Necronum, and is especially talented in weaving. Later on its revealed that she is the sister of Harmony Pemberton, and the aunt to the five missing princesses; Elegance, Honor, Constance, Miracle, and Destiny Pemberton. Despite her status as a Grand Shaper, she disapproves of the High King, aka Stafford Pemberton, and how he rules the Outskirts. As of Book 4, she has assisted and become part of the Unseen.
She is very intelligent of her kingdom's magic, and also very secretive. Since the staged death of her nieces, she has been even more distrustful of Stafford and stays particularly wary of outsiders.
Cole goes to visit her after Mira, Jace, and Joe McFarland get their lifesparks stolen by Sando and his minions. Later on in the story, she enters the spirit version of Necronum to assist Cole in freeing his friends, as well as Destiny, from their prisons within Gamma Rue.