Silvia is a witch of the Darklight Tower Coven and aspires to become a hagraven, thus parting with a portion of her humanity. She is in possession of the Staff of Hag's Wrath. Illia is her daughter and only child.
Illia determines that, because of the acts Silvia has committed out of her desire to become a hagraven, the woman must be stopped. She asks the Dragonborn to help her slay her monstrous mother. Upon meeting Silvia, the Dragonborn must pretend to be a victim for Silvia's initiation to become a hagraven, but will be forced to fight her when the time is right.
Ilia: "Greetings, mother."
Silvia: "Daughter. Who is this you have brought me?"
Ilia: "I found a willing subject for you. Payment has already been discussed, of course."
Silvia: "Splendid! Please take a seat on the chair behind me, would you?"
[After sitting down]
Silvia: "I'll just prepare the subject now..."
Ilia: "I can't let you do this, mother. You have to die now!"