Mask of the Three Fates
From Arkham Horror Wiki
Card info
Type: Masks
Any: Exhaust to place tokens on this card equal to your current Sanity. Then choose one of these unused characters: Sister Mary, Mandy Thompson, or Carolyn Fern. You gain that character's unique ability while you have this item.
Upkeep: Do not refresh this card; instead, discard 1 token from it. If this card ever has no tokens on it, return it to the box.
Clarification
Some encounters refer to this card as the "Triune Mask."