Dragon Age: Shadows of the Blight
The seductive leader of the Chantry of the Stilled Tongue
Mother Brianna wears a black dress, has supernatural claws that deal penetrating damages, and can use her charm power to seduce PCs.
Mother Brianna is in fact a spirit from the fade. She possess the bodies of young women from time to time, around every dozen years or so. She leads a cult of religious zealots who believe that cutting out the tongues of children will prevent heresy from ever being spoken. In a few months after she appears, the cult disintegrates.