Morgantha

The hag of Old Bonegrinder, and a memory broker. She takes people's dreams and most precious recollections and distils them into crystalline orbs.

Beneath her house is not a hag's lair but a Memory Vault — thousands of orbs lining every wall, each holding a stolen memory. She has been harvesting and selling them to Strahd for centuries, and she had been collecting from this party since they arrived in Barovia.