yay! wall of text!

he.. i toyed with a similar idea once... then HD came into being shattering whatever dream i had of a similar idea being actually taken seriously.
anyways. i belive for such project to fruction, it needs to be more of a spin-off than anything.
my idea was somewhat similar, but will still important differences.
for example, keeping belmonts, or Dracula would end being quite awkward if it's not implemented right. imagine a Belmont clan generation formed by.... 567 brothers and sisters? or Dracula getting raided and killed every.... 30 minutes?
my idea was more centering it trough the figure of the castle, rather than belmonts or dracula. you know, every 100 years dracula comes back only to be killed while exiting his coffin by leather-clad whip-wielders, banishing for other 100 years to come.
the point is banishing it to where? well *puts twilight zone voice* the chaoooooossssss dimenssioooooooon.
now lets think.. what would happen if actually people lived there? how do they got there? maybe the castle took with itself an unfortunate village? or whatever, reasons can be made up quite easily at this point. so.. how it's the chaos dimension? i pictured some quite similar to the limbo planescape on planescape mythos, as an chaothic everchanging madness where matter could only keep form as long as there is a will strong enough to shape it to.
therefore the center of the realm would be compromised by the castle. the castle is being keep stable by dracula's will who could either be dormant semy-aware of its surroundings. or just completely aware and plotting his next return, just not caring if one or two bugs creep inside the castle walls.
also , so we are in the chaos dimension where space don't bend to the same physical rules. the castle can easily be gigantic, almost infinite, containing every possible manifestation of it self on earth without having to obey puny geographical restraints of the normal world, meaning that endless dungeons could be emplaced within, and even villages and towns that have managed to blend in the castle.
outside the castle the world wouldn't be so expansive, but still can give the possibility for some creativity. for example, some of the villages that have been swallowed have managed to cling into existence with all their though and might. making not only the village endure in the sea of chaos, but the villagers willpower would also be capable of shaping their surroundings into areas more akin to what their memories retained of the real world. therefore, spawning forests, mountains, even seas, yet the furthest the landscape goes away the village-town, the more fractured, chaotic and surrealistic it turns.
keeping this theme wouldn't be hard to assume that different villages-towns-havens from different eras could been swallowed and "frozen in time" therefore being possible to have a medieval gothic rumanian town surrounded by forests and mountains, or a ruined victorian aged city, where humans inhabit a small ghetto inside the ruins of the town, while the rest of the city being an hostile place. a little like Ravenloft's realms.
now that we certainly have a world to explore that:
A)have some opportunities o put both classic era and metroidvania era aesthetics, as well as drawing from the general castlevania mythos.
B)don't conflict too much with any storyline at all, and feeling like a spin off.
C)kinda (just kinda) makes sense.
D)bringing something more original than another medieval fantasy setting to the tables of MMOs.
we can get a little into gameplay mechanics. so well.. its an online game, it should be an online CASTLEVANIA game, so what could define a castlevania gameplay? at least for me, i feel than action platforming and exploration are what the games tend to be more about. also 2D is quite strong within the series. so it wouldn't be too wild to try a 2D world with plenty of cooperative platforming and explorations besides lots of monsters to kill and treasures to loot. classes should be kept simple yet original, as certainly fighters, clerics, mages and rouges wouldn't fit as well as demon slayers, monster hunters, alchemists, devil forgemasters, priests, witches and thieves (or pirates! yarr!). and why such humans would like to venture outside this dark devillish world? well, maybe the want to steal artifacts from the castle that help their villages survive, or maybe want to learn more about the demons and monsters and their powers? or just carrying the light of holiness to the deepest pits of hell? or find a way to go back to the real world? etc.
obviously this isn't a serious idea... since is more joyful wondering than actually a project but just out of curiosity, let me know if you would be interested/ feel that this would be a not so wrong way of doing it :p