Shyntezca is an Oathbound, and possibly the only surviving Qabalrin Elf. She was a middle-ranking member of the Shapers of Night, the Qabalrin faction focused on the pursuit of necromancy, but she wasn't important or powerful enough to be immortalised as a vampire. Instead, she was Oathbound to the outpost in Taer Umbra. Time has not been kind to Shyntezca, and her physical form has largely withered away, held together by bandages of solid shadow.
Her immortality has been dull and dreary. She cannot leave the demiplane, and for thousands of years she was alone in the dark, awakening briefly to eradicate pests or fiends that found their way to the outpost. Far underground, she was never informed of the usurpation of the Shapers of Night, or the destruction of her people when the Heart of Siberys fell on the Ring of Storms.
It was only when Shyntezca felt the presence of the Umbra that she became aware of the crumbling of the world above. The Umbra is an amalgamation of the souls of the Qabalrin, and Shyntezca now acts as a divine conduit for that power, despite the fact she was not a member of the faction that formed it: the Unspoken. She was nevertheless all they had left, until the arrival of the Umbragen.
Shyntezca now acts as a guide to the Umbragen, and a powerful force keeping them safe. She is powerful, but even she strains under the force that Belashyrra, the Lord of Eyes can bring to bear, and the Umbragen have begun exploring Khyber and the surface to try and find allies to help them.