TL:DR NPC BBEG makes this a 4-star instead of 1.

The good: Yalanue's story is great. Insightful and astute players will realize that this place has been created to protect the heroes layed to rest. Heroes who dont realize that will have the hardest single enemy T3 fight I've seen. And its against one of the most sympathetic and powerful bards in 5e. You will love this NPC and likely pull her into other adventures as a stat block enemy.

The So-So: The DM will have to lean into the story and do a significant amount of improvising or writing to make the entire module feel cohesive and immerive. Its like Claws of Fury, but bland.

The bad: Your players are constantly harrassed by Saresh, a devil who was hired to kill them. But hes pathetic and unmemorable without DM rewrite. Traps are poorly thought out by the designer, requiring some significant DM reworks to make them feel right. As with most of S9, editing errors make the adventure hard to follow. If you like running things as-written, youll find this impossible to prepare or execute well.

I honestly love this mod, but it took me a while to learn how to love it. A dungeon crawl without a map was very difficult to run. I did make my own, but I don't think it did justice to the overall story as I had to make a lot of adjustments to make the map work. The BBEG is by far my favorite boss fight, I loved the mechanics. She is easily a crowd favorite!

Pros:

• Yalanue is a pretty neat boss. Nice touch to give players the chance to not kill her as well; the DM can just narrate as Dara to hint at the alternative possibility. And even if they prefer to kill Yalanue, she has some pretty cool moves and will certainly entertain.
• Optional Mission B is a pretty neat idea as well with the room-filling illusion.

Cons:

• The most obvious problem here is the complete omission of a map for a dungeon crawl scenario. The author went to some effort to describe rooms in detail, but halfway through seemed to run out of gas and made a lot of mistakes that editors somehow didn't find; If you follow those descriptions they start to create contradictory direction relations between rooms. Seriously, why no map? Everything is a rectangular room anyway, could have built a map far faster than the time it took to try to theater of the mind everything (and then go to editing for fixes, which seems to have never happened)
• Optional Mission A really doesn't work. If the players open the door and see the gloomweaver, they aren't all going to walk into the room. And the gloomweaver has no proficiency to stealth, so really there is no scenario in which every player just walks in and falls for the trap. There's also pretty much zero explanation for what the gloomweaver's motivations are or who he/she works for. Why is Vungio hunting the bloody hooves? Why does he/she seek the wards? Who knows.
• No stat block for Dara. Why?

As seems pretty much par for the course in season 9 scenarios, some neat ideas ruined by selling an incomplete body of work. Disappointing.

While I understand that any product of this nature takes a lot of time, energy, and skill to complete, I nevertheless feel let down by the skeletal feel of the narrative, and find that most of the energy goes into building the combat with the big bad of this adventure, Yalanue, and the environment of the dungeon, and that there is little effort to make progress in the chapter compelling through the plot. It certainly doesn't help that Dara, herself, is portrayed as visibly weary. The trap-heavy dungeon coupled with the challenge of Yalanue makes it irksome to me that one would be judged for killing Yalanue by the very High Priest you have to rouse/save, especially since there's virtually no opportunity to sympathise with her. I was left so dissatisfied, I went to buy other earlier products at a similar price range and received much more satisfaction. Disappointing, overall.

My group though this was at best average. Dara is missing from the stat blocks, I used the stat block from 09-15. The B. Entry chamber needs the information where they foyer enters. The passive investigation check is good. But if a pc has the passive, this room is empty except for the combat. The group hated the Musical Chamber so good job there. Part 2 In Playing the pillars Social. Add two DC 17 Persuasion checks to talk Yalanue down. Other suggestions from my group. If strong have monsters roll with advantage, start out as invisible, add fly speed, max hit points if the challenge rating is under 8.