Darkon: An Ideal Grand Campaign Hub

 Darkon is one of the classic Domains of Dread, ruled by the Darklord Azalin the Lich, who was a one-time ally and then later bitter enemy of Strahd von Zarovich before he found himself in his own domain.

Unlike Barovia, Darkon is primarily a Dark Fantasy setting, where all the usual elements of a D&D fantasy world could be found - dwarves and elves, dragons and beholders, etc., - but which was ruled under the iron fist of its undead wizard-king.

In 5th Edition, though, things have changed.

I don't know if it was a module from some earlier edition or what, but the domain had a prophecy of a doomsday known as the Hour of Ascension, in which the dead of the land would rise up and everything would fall to ruin.

And by 5th Edition, that's happened. And Azalin is nowhere to be seen.

Azalin had been the foremost expert on the magical laws of the Mists of Ravenloft, the Domains of Dread, and the Dark Powers, and while Vecna beat him to it, you can trust that no one is better suited to figure out how to escape a place like Darkon than a lich.

Darkon is maybe the most populous of the domains, and has many different things going on in it, but the big thing now is, other than every dead body getting up as a zombie or other undead creature 24 hours postmortem, is that the Mists of Ravenloft, known in Darkon as The Shroud, are encroaching and absorbing the domain while a few individuals have inherited the powers of the crumbling state left behind by the vanished Azalin.

Now, the book plays coy with what actually happened, and leaves it open for Azalin to have been destroyed or captured or something, but they also have a whole entry in the Mist Travelers section for a human archmage named Firan Zal'honen, who happens to share both a last name with Azalin's son and also have an imp familiar named Skeever, when the Darkon chapter also lists "Azalin's familiar, an imp named Skeever" as a potential ally in that realm. So... yeah... Either Azalin's using disguise self and Nystul's Magic Aura to appear human, or maybe he found a way to revert himself to human while also escaping Darkon. Or he's some kind of clone.

Either way, Azalin's deep understanding of Ravenloft and his ancient rivalry with top-billed Darklord Strahd von Zarovich to me says that if you want to run a truly epic campaign in Ravenloft, and not limit it to lower levels to preserve the horror, Darkon's impending doom and Azalin/Firan would make a great figure at the heart of the story.

While Ravenloft is obviously designed to allow you to run a D&D adventure that is claustrophobic and creepy, I think you can essentially effect a genre shift toward epic fantasy when using a character and location like these.

Naturally, Van Richten's avoids referring often to other books than the Core Three, though once or twice it suggests taking some things from Curse of Strahd (naturally,) but if you want to graduate from the horror genre into something more epic, I'd really recommend looking at Mordenkainen's Tome of Foes.

The Dark Powers are intentionally kept vague, and while the book does confirm at least one of them to have originally been a lich, I think you could take great liberties, and even forge some or your own apocrypha. What if the Dark Powers are (at least in part) actually the Dukes of Hell, and so an effort to combat them could draw in foes like Bel, Geryon, or Hutijin? Or you could look at the fact that Ravenloft is, after all, a part of the Shadowfell, and have horrifying shadow creatures like Nightwalkers represent the Dark Powers' wills made more directly manifest.

You could also even imagine them to be celestial beings who have created the domains to sequester greatly evil beings away.

Most of the really iconic monsters in Van Richten's itself cap out at about CR 13 - I don't really see any individual monster being terribly scary for a party that's made it to tier 3 except for the Star Spawn Emissary. Again, the book is very much about how difficulty and a monster's toughness isn't necessarily what will make it scary, but I do feel like you could really change the whole tone of the campaign by embracing a larger scale and a more epic storyline after the initial haunted castles and ancient tombs are cleared out.