Overall a good module, with a few issues. Mostly a "traps" module, the issue is that the traps really have no clues around of what to do. A lot of them are either unintuitive or just impossible to figure out. For instance, while the "skull room" does have a clue, five consecutive DC 19 Medicine checks is a bit high, especially if you don't have someone proficient. Similarly, there's no way for the party to know that reciting the prayer over the entrance is the solution to not getting sprayed with acid. They spent quite a lot of time trying to figure out how the eggs fit into the puzzle, which I think was because there are four statues and four eggs.
Also, if there are any yuan-ti in the party, all of the traps are basically trivial, because they basically all do poison damage.
The encounter with Satszehsu is odd, to say the least. It's not clear what the party's supposed to ask them, or what helpful information they can give. I will say that I really appreciate the they/them NPC!
While it was a fun mechanic to have people running back and forth through the trapped hallway, ferrying talismans and trying to avoid being hit, I don't think it was intended, but there are only four talismans, so it was basically unavoidable.
Ihl and Nozhi are incredibly weak. They didn't even last one round. I do like the tie-in of Rhaugilath, but to my players it was just very odd. Overall, a strong module with a lot of story tie-in.
[4 of 5 Stars!]