As I mentioned on Twitter, I'm now considering multiple oracles (well, two at least, possibly three) for my Castle Dracula idea. But as you said, I don't want the game to drag on for two long. (Though now that I've said that, I'm rather interested in knowing how long a game can go, and if it'd continue to be fun.) Other ideas I had on making the tower fall faster after each reset were 1) rolling more dice for initial pulls, and 2) having cards that force multiple pulls.