Theriana is a powerful human wizard in the service of Lolth.
Very little is known about this enigmatic figure. She is tall, with piercing green eyes, long blonde hair, and an almost unnaturally beautiful face. She has typically been seen wearing the black robes common to the Cult of the Spider, and while the extent of her magical skill is unknown it is certainly very high. She was at the forefront of the search for the scattered keys to Lolth's prison, and encountered the Brightstone Heroes on a number of occasions, though never engaged them in direct combat. A genie claimed he had once been enslaved by her, and described her home as being a massive, spectacular city. However, when he sent the heroes there, they arrived in the ruins of Estorium.
Acererak's Soul Gems
After Tephra opened a portal to the Far Realm, Theriana approached the Challengers of the Unspeakable outside of Silverstone claiming to know a means of closing the it. When they agreed to help her, she sent them to the Tomb of Horrors to bring back Acererak's soul gems while she herself sought out the Pyramid of Shadows.
She appeared again during the Battle of Silverstone, helping to battle the aberrations before asking the Challengers of the Unspeakable to give her thesoul gems. When they refused, she departed after promising that she would get them one way or another. That night, she attacked and captured Myra Brigg, promising her safe return in exchange for the soul gems. Priam Adenis and Leardon Sunflare went after her, but it turned out to be a trap and they were both captured.
Theriana imprisoned Priam within the Pyramid of Shadows and took his wedding ring, which was enchanted to teleport the wearer into the Trine Academy. Once inside she began laying waste to students and teachers alike, releasing various monsters from the Pyramid of Shadows to keep any pursuers busy while she searched the vault for the gems. When the Challengers of the Unspeakable caught up with her she easily fought them off, only to discover that the gems in the vault were fakes.
Suspecting that the gems were in Estorium with the army fighting the Far Realm incursion, she traveled there with a retinue of drow and staged an attack to take them back. Though the attack appeared to fail, it was a ruse; a doppelganger replaced the wizard who held the gems, and used the recent attack as an excuse to convince the Challengers of the Unspeakable to escort him to a hidden location away from the main camp and promptly delivered the gems to Theriana once left alone. Once the gems were in her possession, she attached them to the Pyramid of Shadows.
One of the individuals released from the Pyramid was a sorceress named Vyrellis. Though she initially agreed to help Theriana in exchange for being given rulership of Estorium, she soon concluded that their goals were incompatible and allied with the Brightstone Heroes and Challengers of the Unspeakable. After arranging for the Challengers to be captured and imprisoned within the Pyramid of Shadows, Vyrellis helped them overload its magic from within and force it and the soul gems attached to it to teleport away from Theriana, shortly before triggering a magical explosion that destroyed her camp. She has not been seen since.