Vastienne is a demigoddess, the daughter a goddess of magic named Sorcharine (who died during the Gods' War, but that's not common knowledge.) Her powers manifested over two thousand years ago, when she was just 14 years old. She is the only demigod known to have manifested divine powers that young. She's 5'2", pale and slender, with large, almost translucent eyes, and a heart shaped face. She always dresses extravagantly, with flowing hoop skirts. Her long pastel hair is always done up in high, elaborate styles.
Vastienne is the highest authority among Blackmire's supernatural sect. She however, secretly afraid of Cho. Not that she would ever admit it. Sorcharine was an Ascendant God, transmutated through a combination of her own power and the energy sacrificed by follows who began to worship her. Cho's divine parent, on the other hand, was an Elder God. He was birthed in, and possibly by, the Abyss. Vastienne's strength is no match for Cho's, should Cho ever choose to flex her powers. Fortunately for Vastienne, Cho has no interest in supreme power.
Vastienne is brilliant, formal, articulate, pretentious, snide, manipulative, mysterious, auspicious, superstitious, and haughty. She's an übersorcerer; magic comes as easy to her as breathing. She's curious and easily bored; she likes to do things simply to see what happens.
She believes relics are too powerful to be allowed in the hands of lowly mortals. Jao is her personal thief, her play-thing, and by extension, so is Locksley. She likes to wind them up and watch them go, just for fun. But as much as Locksley would enjoy killing her, if Vastienne dies, she would leave a power vacuum. She may be annoying, but she's better than the alternative. So Vastienne is untouchable.