I'm not speaking in terms of continuity, although that can apply, too. How would you re-shape the Castlevania mythos to your ideal vision? Not as in gameplay, but within the fictional elements themselves.
For me:
*Bring Dracula more in line with Stoker's novel. So make him fit the description, have the same powers, and the same weaknesses. Which means no death by sunlight. I hate that it has become so engrained into the character. Well, he's out during daytime in CV64 if its the right time. But I digress.
*Piggy-backing onto the first bullet, have the games add more to the elements of the novel. He has three vampiresses in his castle. Maybe they're characters within CV story that get turned?
*Get rid of Alucard. The name, not the character. It's corny. Just let him be Adrian Fahrenheit. No Tepes. It's a title, not a surname.
*Elaborate on Frakenstein('s monster). He's in so many of the games, usually in a lab setting, but there's never much in the way of fleshing out the character. Also, address the fact that the Monster is being created centuries before Mary Shelley's novel takes place. Maybe having Dracula's books of alchemy somehow end up in the hands of Victor Frankenstein. Don't know.
*Keep Trevor as the first Belmont.
*Quincey Morris kills Dracula once and for all. He's not a Belmont. His name is spelled correctly.
*Incorporate more traditional vampire remedies/killing methods.
*Do away with the 100 year resurrection gimmick.
*Let SCV4 be a sequel like it is in the West. Simon's story needs proper closure after CV2's ending.
*Let Dracula X be a sequel to Rondo as it gives the impression of being so.
*Explore the origins of other vampires and monsters, i.e., Carmilla, Mummies, Medusa, etc.
*Fix the name translations to their intentional references. Fernandez instead of Belnades, Ricardo instead of Lecarde, Orlock instead of Olrox.
*Bring back and explore the Tower of Colbert. Ever since I first read about it in the VK manual, I've been intrigued. Where is it? What's there? Is it the tower where you confront Dracula?
*Incorporate loyal gypsy slaves of Dracula as villains for the Belmonts to confront.
*Alucard is a vampire, not a dhampir. Dracula gives his unborn child's body as payment for his own immortality. So Alucard is "born" undead. He has a conscience, he loves and wants to do right, but his darker impulses forever haunt him.
That's all I can think of off-hand. I'll probably add more later. Your thoughts?
P.S. Sorry if this thread already exists. I haven't found one. Redirect me, if necessary.