The combats are challenging. The story is compelling. The players have a reasonable amount of agency. All in all, very nice.

This mod doesn't pull its punches. I think it's one of the most dangerous ones I've ever run as a DM, up there with DDAL05-11 and DDAL07-18. That's great if you have experienced players who know their strategies (action economy, kiting, and so on). If your players are less experienced, though, don't be afraid to go a little easy on them.

My biggest complaint is that the cutscenes are too long and contain redundant exposition. Dandelion explains a bunch of stuff, then Tal'daynath explains a bunch of stuff, then Dandelion explains a bunch of stuff again. Luckily the story is, like, actually very good and well thought-out, so it's not too bad. I'd actually seriously consider skipping the scene with Tal'daynath and running one of the ambushes instead, though—as cool as the character is, Dandelion can impart most of the same information, and the time spent talking with him may be time that some players spend unable to participate due to the dullahan unraveling curse, which is a potential feel-bad.

Ultimately, this is very well done. You can tell a lot of love and care went into it, and I'm pretty happy with the result.