You don't have to do a "weekend in hell" adventure. You can do Ravenloft as domain natives, Ravenloft native, or a long term Mist-Grabee.
My opinion is that even if you are using some random monster, mage, slasher, cult, or vampire as your enemies, it's not Ravenloft if they aren't linked to a darklord. Tortured by them, created by them, funded by them, rivaling them (on their way to be one themselves)
Even in a darklord-less place like late Darkon, you are still dealing with nonsense the lich left behind and the fear that he comes back. And there is probably some idiot trying to bring the darklord back, call in other one, or transform into one.