Sylvia Anna, known to a few as Syanna, is the older sister of Duchess Anna Henrietta of Toussaint and a distant cousin of Emhyr var Emreis. She was born during a solar eclipse, and the court believed she carried the Curse of the Black Sun. As a child she suffered terrible nightmares that only stopped when her little sister slept beside her, and she loved the Land of a Thousand Fables that the illusionist Artorius Vigo created for the two princesses.

Because of the curse, Syanna was exiled from Toussaint as a girl and treated cruelly by the knights sent to escort her out. Years later she returned with a plan for revenge, using the love of the higher vampire Dettlaff van der Eretein to kill the men who had wronged her.

She is one of the central figures of Blood and Wine. Geralt’s choices, especially in the Land of a Thousand Fables, decide whether the sisters reconcile and whether Syanna survives the story.