I picked up Van Richten's Guide to Ravenloft and have been reading it cover to cover. This is my review of the book, chapter by chapter. Chapter 3 covers over 30 domains, so I'm posting about it as I work my way through the different domains.
This is the final featured domain in the book, meaning that the next section is a collection of one-paragraph domain descriptions of the "left overs". Valachan is a domain of rain forest and jungle and seaside. It's an untamed region, with clusters of civilisation that include not just a few weretigers and werepanthers. Giant beasts roam the forest, always on the prowl, and yet also in danger themselves from the fiercest huntress in all of Ravenloft: Chakuna.
In the 3.5 version of Ravenloft, Valachan's darklord was Baron Urik von Kharkov. He was actually quite a tragic figure, having been a werepanther abused by an evil wizard. After escaping from the evil and abusive wizard, he got mixed up with the Kargat in Darkon, and was essentially enslaved by a vampire there. After escaping from the evil and abusive vampire, the Dark Powers granted him his own domain. Unsurprisingly, considering his upbringing so far, he turned out to be an abusive and evil leader.
In the 5e version, Chakuna from the village of Oselo has decided to put an end to the baron's reign of terror. She burns his palace and kills him. (She also rips out her own heart and eats his, which is some seriously cool mythology.) This makes her a liberator of Valachan, and a hero, and so she's uniquely a darklord by choice rather than by imprisonment.
This brings up a lot of questions about the nature of 5e Ravenloft. What happens when the assigned darklord is vanquished? It was stated at the start of the book that most people in Ravenloft lacked souls because they were just pawns that the Dark Powers used to torment the darklord. In this case, it seems that one of the pawns has done away with the darklord, so is this a domain that's just running a simulation for the sake of the simulation? It doesn't make much sense to me.
The central plot of Valachan in 5e seems to be the Trial of Hearts. This is a battle royale trial by combat, in which the winner gets to not die, and also gets escorted out of Valachan. Chakuna herself takes part in the trial, so you're as likely to be killed by her and her pet displacer beast as you are to be killed by any other contestant. Part of the Trial of Hearts is also to find a shrine while not being killed, so there's plenty of opportunity for a dungeon delve into a forgotten jungle temple, a nearby seacave, or whatever you dream up.
This seems like a pretty simple plot, and it's absolutely sufficient for an adventure in Valachan. The darklord is intriguing and, I think, could easily be incorrectly demonised until the very end when it becomes clear that she's holding the Trial of Hearts to weed out evil, or something like that. Or you just could play her as a revolutionary who's succumbed to megalomania.
In fact, this one's intriguing enough to me that I could see it being transplanted into Chult as a possible subplot on the way to the Tomb of Annihilation, or even as a plot for an adventure on the very far away Starfinder setting of Castrovel. It's a jungle setting with a strong story and a buncho f sympathetic lore.
Valachan is the last domain of dread that gets six pages of coverage. The next section breezes past all the other ones every mentioned in past Ravenloft publications, so I'll cover that in my next post.