I like Kartakass more than I expected to. It's been a while since I've read any of this stuff, and I remember it as always being one of the 'meh' domains for me, but rereading, it's characterful and interesting.
Our narrator starts with the usual overview of the geography and general landscape. We're talking deep rich primeval European-type forest here, blanketing a hilly lamscape, with the very few sizeable settlements clinging to major rivers. Logging is a big deal but never seems to actually reduce the forest's size. Enormously fertile, all sorts of trees and vegetables grow enthusiastically in black soil.
Kartakass is all about the wolves. We have a mundane sort of fauna here for the most part, as opposed to the howling ghost-and-goblyn-ridden wasteland of Forlorn or the radiomagical mutants of Hazlan. Wolves, boars, owls etc, including quasi-mythical dire and giant versions. There's a nice little anecdote about finding a wolf-eaten corpse of a dire boar - it's described as being a daunting beast 'the size of a wagon' which is quite a mental image when you picture it in front of you. But it does raise the old saw about the appropriateness of the D&D ruleset for a setting like this. In 3e a dire boar was something like CR4 if I remember right. Hardly much of a challenge for any group of about 2nd level or higher. In 5e it's even less threatening - and the pace of 5e leveling early in the campaign means that PCs will advance way beyond it very fast. Making a critter like this frightening to a tougher group? That's going to require some major statistical surgery. There's a definite assumption in a lot of Ravenloft setting material that PCs will be low level.
Of course the place is lousy with wolf shapeshifters, both werewolf and (mostly) wolfwere. Our narrator goes out into the wilds with the aid of a helpful local, hoping to find some. On being assured that our narrator's pistols are loaded with silver against werewolves, the helpful local cheerfully assumes his true immune-to-silver wolfwere form - only to be magically paralysed and then forensically dissected alive in the interests of scientific research. Yikes. Narrator certainly saw you coming, guy.
On a technological note - this little anecdote also seems to illustrate that firearms are sufficiently widely known in the Core that even a logger in a backwater like Kartakass appears to be relatively familiar with them. They may be expensive or hard to obtain, but people know what they are.
We then have history. After the pages and pages of ancient Forlorn and Hazlan history int he last two chapters, this comes as something of a relief. Long-ago Kartakan history is more allegory and fable than a list of names and dates. You have myths and tales of Grandfather Wolf, Grandfather Boar, and Grandfather Owl, which resemble the Dreamtime stories of indigenous Australia or Aesop's Fables or the Brer Rabbit stories of (I think) American slaves. This actually makes a fair bit of sense in a bardic oral-tradition culture like Kartakass, and I like it quite a bit. There's a bit more recent history which is basically the Kargatane outlining the events of Feast of Goblyns and the novel Heart of Midnight from a slightly-better-informed-than-average in-world perspective, and to be honest it reads a bit awkwardly. What it does do is establish Harkon Lukas as something between an institution and a folktale. He's been around for hundreds of years (the locals think of him as an archetype like Grandfather Wolf, the name 'Harkon Lukas' a mantle worn by bard after bard), he's been the guy who chooses rulers or overthrows them, and currently is one.
Culturally, the place takes a lot from Grimm's fairy tales, there's a distinct rustic Germanic quality about it all. Poor farmers and loggers singing all day, fine woodcarvings on even the poorest house, beets and borscht and brau and those William Tell caps with feathers in them, a very low-key local and locally democratic government led by the winner of a singing competition (there are rules for entering the singing competition). It's almost anarchic in its idyllic facade of a happy rural populace who mind their own affairs, largely. Unless they're a wolfwere who wants to eat you, as we are reminded many, many times in the text. There are a couple of smallish towns (Lukas is the meistersinger of Skald, the larger one) but the population is widely scattered and every little hamlet has its own meistersinger. Religion is low-key - vague ancestor-reverence, with an emphasis on coming up with a song in your lifetime that's memorable enough that you'll be part of the ancestral choir too once you die. The formal church was founded by a previous meistersinger (later proven to be a wolfwere) and has few devout adherents, and generally struggles a bit.
Lukas is an odd darklord - possibly because he's one of the oldest (in real life) and stems from when TSR was still really figuring out the ground rules of Ravenloft, domains, Darklordship, etc. There's at least two novels about him which I read about 25 years ago and have almost completely forgotten, but from what sources i do have, the implication is that he's a wolfwere who craved power in the human world and was shunned among the more traditional wild/predatory wolfweres because of this. The character outline has him spree-massacring a mass of human farmers out of frustration with this state of affairs and being taken by the Mists after that, but it's an unanswered question whether he drew the notice of the Dark Powers for this massacre, or for the more subtle sin against wolfwere morality he committed through his ambition. Are the Dark Powers somehow moreal relativists who punish transgressions against monstrous moral codes and mores? In any rate, his damnation seems to have been to be penned in a tiny rustic backwater domain when he really wanted prominence, power, and rulership over great nations. He's made the usual couple of attempts to escape or to expand his domain through trickery, but Dark Powers said no. He's a manipulative, cunning, backhanded liar and a charming bastard who people believe even when they shouldn't. He's a very personable Darklord, and ther PCs are quite likely to bump into him as he wanders around Skald, and he offers a much different roleplaying dynamic than the various versions of Tristen apBlanc lurking in his castle or Hazlik who's probably only going to be interested in the PCs as experimental material.
As for using Kartakass in a game ... again, you have to have a reason to go there. There's a note saying that the best musical instruments in the Core are made here, so that might be motivation for a bard, especially one who wants to craft a magic instrument. And if PCs want to travel between Hazlan or Forlorn to Sithicus or the domains beyond, then riverboat through Kartakass is a pretty good way to do it. It'd be a pretty good place for an actual campaign though - the diffuse (and frequently furry and wanting-to-eat-you) government will often stay out of the way letting PCs do things their way. If you want to play a site-based, village-building type game with lots of recurring NPCs, (or a game where the PCs run a riverboat...) then Kartakass would be a great choice. And in Lukas, you've got a Darklord who is widely-known, accessible, even approachable - you can build up a good rivalry or emnity with him over a long time, he's not just going to crush you like a bug like Azalin or someone might. One issue might be the lack of variety in enemies. It's wolves, wolves, dire wolves, werewolves, wolves, wolfweres, and wolves. While there's a couple of sites that offer some variation, that's still going to drag in a long campaign, unless you introduce additional factors from outside.
As a 'weekend-in-hell' location, it has potential too, though it is something you'd have to write yourself from scratch. I don't think there's a quintessential 'Harkon Lukas' module from back in 2e - even though he appeared in Feast of Goblyns, i don't think he was the focus (and I don't think the module even really took place in Kartakass). Even using the soon-to-be-gone Core geography, it borders the Mists, so you could find your way there anytime you were wandering through a sufficiently deep forest and the mist rose. Obviously as an adventure location rather than a campaign location, wolfweres are going to be your bad guys, you're going to be chased through the woods by howling murder machines at some point, and someone you trust is going to turn furry and try to eat your head, and it'd be very easy to have Lukas conducting the whole situation as part of some machavellian plot behind the scenes, whether the PCs ever find this out or not.
Random class generator gave me rogue today, which was a relief because i have no idea how i'd have done a Kartakan wizard or warlock. Kartakans are merry types who like to wear bright colours even if they're hard up for funds. So this PCs is a poor but personable orphan (parents got et...) who roams the river, doing a bit of trading and a bit of guiding and a bit of trapping or guarding to earn a crust, supplementing it with some light thievery when things get tight. But she doesn't really like doing that, so if there's an opportunity for treasure-hunting in good company, she'll be on it like a shot.
That's the last domain in Gazetteer I, so next is a few notes on the book as a whole, and then it's on to Darkon.