Friend Vilnia was a Mechanist Priest and appeared to be in charge of the day to day running of Angelwatch. While Karras was away, she acted as Host to the nobles at the Party at Angelwatch. She was also fairly trusted by Karras as evidenced by her knowledge of some of Karras's plans, like the trap for Garrett[1] and giving her the only key to his office[2]
Notes[]
In the Thief 2 Demo, Vilnia is a male, with the name of Vilnius.