Redfall is building on an old Dishonored idea, pocket worlds. Only now, they don't house the Outsider - they're holes in dimensions punched through by god-like vampires.
These incredibly powerful vampires are capable of warping reality around them thanks to their psychic abilities. This is how they trap you on the island and black out the sun. And through your quest in Redfall, you'll be tasked with hunting them down, with each vampire god serving as a chapter break.
However, what's really interesting is the other worlds they create. They're familiar but alien, warped and contorting on themselves like backroom liminal nightmares. They're styled with Halloween in mind - the season, not the film, so don't expect any babysitters fighting for their lives - and built to look just like that. Horrifying nightmares made reality.
These pocket dimensions aren't just a neat little gameplay twist that gives you a whole other place to explore besides a small town in the USA. Vampires go to these pocket dimensions to gather power and sleep, protected from the real world. It's much harder to get backstabbed when you're not even in the same universe, eh?
They're designed with Arkane's approach to vampires in mind. These aren't mythical fairy tales brought to life, though they're still bloodsucking nightcrawlers. They're rooted in science with each of them being powerful people who were already vampires at heart, now finding a literal way to enhance themselves. Vampirism isn't a disease or a plague in Redfall - it's an evolutionary step for the villains who claw for it.
Arkane describes it as a "metamorphosis" which is why they look so exaggerated and borderline monstrous, despite wearing fashionable Victorian-era garments. Vampire gods reach the peak of that power clutch and these pocket dimensions are just a glimpse into how capable they are. It's gonna be tough for the group to take them down, but there's always the garden gnome stake attachment to do it with. Sadly, killing them is the only option - you can't romance 'em.