I just beat the two sisters. Got the fake ending, and it's like "ok, my daughters..." and that's it. Normally these endings give you at least a hint how to do it. Even the priest is like "there is a purification spell, i'm a vampire, please heal me." so there's a huge hint right there. Ok... WHERE do I get that?
I read Viz's spoiler on how to get Sanctuary. HOW are you supposed to know where to get that? -50 against Portrait of Ruin for that alone. I'm not crawling this entire castle to find some spell that I have no idea how to find (prior to reading Viz's spoiler, and even his spoiler doesn't help. What enemy drops that?).
Guess it's off to GameFAQs.
This game is the shit, btw.