I have a group that just started Curse of Strahd. They're one session in. I have a character that couldn't make it first session, and I'm in the process of “writing him in” so he's with the party for the second. He's part of the writing-in process… we go back and forth with some emails with some RP decisions on his part, but I am pretty strongly guiding him to where the others are.
Anyway, quick backstory, his sister was captured by a cultist long ago, he tracked them down to some location in the woods — enter the creeping fog hook — he gets lost in the fog and pops out in Barovia. In a truly “against all odds” moment that only happens in movies, he stepped on a locket in the dirt that belonged to his sister. And he stands, emboldened, knowing the cultist and his sister are also trapped here in this mystical valley.
Enter my dilemma. I am fully willing to have it so that the cultist and his sister are truly here in Barovia somewhere. But, I am also considering making it so that this locket… and for that matter any other evidence he finds regarding their whereabouts here in Barovia up to and including the cultist and his sister… is an illusion. Or more accurately, a manifestation of his emotions/desires.
I've never run Strahd before, so I'm still working out the feel for the campaign and exactly how much power Strahd has in this demi-plane of his. There are places in the book where it says creepy stuff like “the character sees herself hanging from the gallows and when she touches it it turns to dust”. So there's an element of your own self projecting the horror. Also Strahd has god-like abilities… hearing prayers not directed to him, showing up in some assassin mirror….
Does Strahd inherently know of this character's past/desires (read: can I metagame the crap out of this)? Or does Strahd need to come by that information honestly?