Melusina, Sage of Avalon

After you finish a quest while Melusina is in your party, you can either draw one card or gain 2 summoning stones.
You can sacrifice Melusina to negate the effect of sorcery while it is being revealed by
the encounter deck.
"According to medieval tale, Melusina was one of the
three sisters lost on the Isle of Avalon. Melusine, the
eldest sister, was cursed and forced to spend one day
a week as a raven wraith."