SPOILERS Did you have the pink spellbook, in addition to the brown spellbook? Giving the mage the pink (wrong) spellbook deals with the vampire. If you don’t have the pink spellbook, that’s a major bug I need to resolve.
And just checking: have you been right-clicking on the potions to re-read their rules?
Glad you’re enjoying! I knew the vampire vs Skee would get people XD