In Curse Of Strahd, Norganas' sarcophagus was encountered by the Heralds of Dawn. She had little power to contact the adventurers as she had recently used their abilities on another champion, and had failed to get them to break her prison.
An ageless Dark Power native to the Plane of Shadow, Norganas was once a higher being who preyed on souls within the veil of the Deepmists. In the Pre-Unified Age, she was locked into an amber sarcophagus by high mages of the Azure Paragon, then was stored in the Amber Temple alongside other Dark Powers. Claiming the title "The Finger of Oblivion," Norganas asserted to have ultimate power over negative energy manipulation, but was only able to influence the realm beyond her tomb with minor magic.
As her powers waxed and waned during the Barovian Calender Timeline, she contacted adventurers to harvest soul energy from Barovians. Like all Dark Powers, she had methods of feasting on souls departing mortal's bodies, and in exchange for magical power, would request that her champions destroy their sarcophagus. However, she experienced few successes, as souls leaving Barovia were nearly always consumed by Vampyr, and her champions were killed by the many horrors of the valley.