Yeah, it's not really a hard thing to do. You just have to create the mythology and backstory to act as a great "backbone" for your world. Dracula's public domain, but I wouldn't be against someone new. Could be Orlok(Graf Orlok of Nosferatu fame, who was also Olrox in Castlevania), Carmilla(for a nice change to have a female villain be the main threat of a series), or just make up a vampire. Call him/her Count Vladak or Lady Stygia, come up with their backstory and how they became such powerful vampires, their connection to the heroes(heroic family, which I like) and roll with it.
Though, considering this might revolve around Alchemy, it could go more a dark magical route. The hero is probably an alchemist who must use his skills to fight against a villain that has defied nature and created a castle of monstrosities and using Alchemy and wisdom from eldritch tomes to become something inhuman.
