The Blood Steward of Kirtonos was a level 43 elite succubus found in the Reliquary in Scholomance. She was added in a patch as an additional source of Blood of Innocents. But to get to her, you need to clear nearly the entire Reliquary. It was optional to kill her, as Jandice Barov and Doctor Theolen Krastinov will also drop the Blood.