Verbrek.
Kartakass, but more so.
I could honestly leave it there, and in fact this writeup is probably going to be shorter than most because there's simply not much to say. It's werewolves rather than wolfweres, but it's almost entirely the same Kartakass tropes, turned up to 11. The lycanthropes are more populous, the human (again, the tiny non-werewolf population is 97% human) populace even more isolated and terrified and huddled in rough-hewn farming hamlets, shivering at the sound of the howling in the night.
Geographically, it's a forest. There's the slightly more swampy bit of the forest, the slightly more hilly bits of forest, but not much more variety thatn that. This is nature primeval, there's explicitly not even any ancient ruins here. The largest settlement listed has a population of 67. Small palisaded villages cling to the rivers, working the waterborne trade with Richemulot and Invidia, exchanging furs and fish for manufactured necessities while subsistence farming, fishing, and hunting for everything else. The monsters are fairly standard. Every possibly variety of wolf, a smattering of other wilderness lycanthropes, some dire animals, and monstrous plants. Again, basically the same as Kartakass.
History here is wolf history rather than human history, and it's very fable-like, again, reminiscent of Kartakass. The savage Wolf God ruled over all before humans came along, and when humans started to cut down the forests and clear the land. The wolves couldn't stand up to the metal weapons of humans, but there were a fraction of humans who admired the strength and savagery of the wolves in this long struggle, so the Wolf God turned them into the first werewolves to keep the weak farming humans in their place. Now Verbrek's unquestioned rulers are the werewolves. Humans don't worship the Wolf God, but do fearfully seek to placate him with prayer and sacrifice. No human family has more than two children - third children are believed to be dragged off by the wolves, as the Wolf God won't tolerate human numbers increasing as the generations pass. As far as human history goes - there doesn't seem to be any. Human Verbrekers are scrabbling to survive, they're not scholars or historians, and there's not enough of them to really even worry about politics. The last harvest is much more relevant than the last century, but also, there's a feeling of timelessness here, as if history does't matter and this bloody dance of human, wolf, and werewolf is the way it has been since time immemorial and is the way it shall always be.
The darklord here almost feel peripheral. Alfred Timothy is a werewolf, a sickly child who found strength as a fanatical priest of the Wolf God. He's got a point to prove to his werewolf father Nathan (the darklord of a now-defunct neighbouring domain) who despised him as a weakling. Roaming around perpetrating deeds of ever-increasing savagery, he was caught and due to be executed, but his life was bought by some Vistani. They offered him freedom in excahneg for free passage for their people in perpetuity, he agreed, and then killed them the second his bond were loosed. That earned him his domain, and later on in one of the Core's periodic realignments, it seems the Dark Powers at least agreed he'd out-savaged his dad, because the two domains merged, he became the sole darklord, and the Dark Powers just ... released his father who now cheerfully sails a riverboat around the Core. Huh? His father gets a writeup too and is still a murderous chaotic evil werewolf, no repentance or anything in sight, what the hell happened there? Did the Dark Powers just get bored or something? Anyway, Alfred's curse (unclear whether it's from the Dark Powers or the Vistani) is that he reverts to his human form in states of high emotion. Which is actually a fairly good one. He reveres savagery and primal instinct, but has to remain logical and collected or his prized physical strength will vanish and the other werewolves will turn on him. His father derides him as weak and not a real man(/wolfman), but his curse won't let him take a mate or sire pups. He's toxic masculinity in fur, preaching a standard of brutality and might that he despises himself for being unable to live up to himself, and compensating by demanding every more extreme expressions of savagery from his followers.
However - it really seems to me like the true darklord here is the Wolf God itself. Timothys come and go, father to son, but the Wolf God and the wolves that lurk beyond the firelight and the palisade remain eternal. Maybe that's why Nathan Timothy escaped his domain so easily - he was never the real prisoner...
There's a few attempts to add complexity to what is a fairly stark and simple place. There's some disagreement among those werewolves who live secretly among their human prey, those who live as close to natural wolf lives as they can, and those who live in the wilderness but believe raiding and slaughter of humans is a sacred and joyful duty. So if you want to dive into werewolf politics, you can. There's a secret society of Verbrekers who seek to overthrow the Wolf God, but have to conceal their activities from their fellows who are fearful of retribution. There's a small hospice for infected lycanthropes of all types who seek to control their curse (and a prestige class for them, so if we have rules for playing PC lycanthropes in the 5e book, we can't pretend it's WotC mainstreaming Ravenloft for the kiddies, the option's been around for a while), and there's an association of non-wolf lycanthropes who band together for mutual assistance (this doesn't mean that they're
nice). But in the end, this place is about the wolves.
Using Verbrek in a game ... hmm. If you want to do a survivalist one-shot with lots of werewolves, you do it here, and this is what I'd expect the 5e incarnation to look like. It's spartan and isolated and the feel of being a tiny island of humanity in an ancient hungry wilderness is really uncompromisingly in-your-face. None of your Kartakan singing mayors here, it's fear and blood and barring the doors at dusk and shuddering at the sight of the full moon. The darklord I find uncompelling, he's a monstrous, irredeemable character, but the feeling is that if you kill him, the next strongest wolf would just step up to replace him, and so on forever. But on the other hand, that means that you CAN kill him without breaking the domain, which could be a decent campaign goal. Problem with Verbrek as a setting for an ongoing campaign though, is that there's nothing here and very little reason to come here. Even if all your PCs are Verbrekan natives, if they stay there they're never going to find (or spend) much in the way of treasure, and there's not really much in the way of variety to the encounters they'll face. Get used to fighting lotsa legendary/dire/were/wolf/weres and the like.
On the other hand, it's probably not the best setting for some other sorts of werewolf stories, where you have a peaceful village suddenly beset by savage murders by a claswed creature and you'e not sure who/what is responsible and which villager has the deadly secret. There's just Too Damn Many werewolves here, you lose shock value. The locals are just going to be 'oh crap, someone got infected, who is it this time?' Best run that sort of story in a more cultivated domain, Richemulot or Mordent or even Darkon or somewhere.
We get a bit of metaplot at the end. S goes to seek out the Circle, a place where she believes werewolves perform their rites to the Wolf God. But shock! Her guide, a supposedly reformed infected werewolf, is not reformed at all, and gives her away. She blows him away with silver bullets, but is wildly outnumbered. The high priest (Timothy?) tells her that she is the quarry, and that she should run. She runs, but the wolves are faster, and they catch her and seize her and she feels the fangs sinking home ... and everything fades to black. Ooh, a cliffhanger!
Random class generator gave us warlock. There's REALLY not many warlock patrons appropriate to Verbrek's primal, savage feel, much less the rustic book-wary inhabitants. Genies? Underwater monstrosities, in a domain that doesn't have a coastline? Undead, in a domain where raw savage life simply pulses in the air? Fiends or great old ones, in a place where there's no ancient unspeakable tomes to learn their names from? I do hope that maybe a future Planescape 5e setting will resurrect the Animal Lords as warlock patrons, that could work nicely. Anyway, out of sheer lack of alternatives, I'm going with an archfey warlock here. There's no fey in the recommended monster list, but it's a primeval forest, right? Anyway, this is what happens when you get caught away from the village late at night under a full moon, and crawl into a hollow tree in the hopes the things hunting you can't reach. Some trees already have inhabitants, and this one will make a bargain with you, sanctuary for the night, and power for the future, in exchange for a promise to always go barefoot in the forest, and, once a month under the dark of the moon, to feed the tree with a fresh heart...
Next, Valachan.