I'm of two minds when it comes to this book. I'm giving it 4/5 stars anyway because I think it is the best possible rendition of what this book can be, and I'll get to that in a minute, but let me explain my issues first.
My main contention is that I would have been fine with it if after Magician's End, Feist had have washed his hands of the Riftwar and said, "This far and no further. This story is over." The Chaoswar trilogy was a good end to that saga! Everyone I've ever spoken to has more or less been on the same page about that. Admittedly, I think you'd have to have been a pretty diehard fan to get that far, but all the same, it was a good end to the Riftwar saga.
My next contention is the continuity lockout factor here. The first couple of books of the Firemane trilogy were a pretty good pair of books that had no real continuity lockout that pretty much anyone could pick up and read and understand, even if they'd never read a Feist book before or even if their only Feist book had been Magician, and even if that had only been once twenty or thirty years ago. It was an easy in to Feist's work, even if you weren't super familiar with the Riftwar saga or you hadn't even heard of him before.
That was always going to be a concern, too. A couple of years ago when I was reading the Riftwar saga, I remember reading a review here on Goodreads for one of the later books--I really want to say it was for one of the books in the Darkwar or Demonwar series, but I could be wrong here--from a reader who hadn't read any of Feist's previous works and had picked up a copy of the first book in his then-new trilogy. He'd given it a two star review and basically just said, "Hey, I've been locked out of the continuity and I don't understand what's happening."
Someone like that would have that exact same complaint about A Darkness Returns. It may even be worse here because while a lot of Feist's previous books will explain things as needed, this one is referencing a lot of what's come before and expecting you to more or less understand what's happening. When I read that other review for that other book two-ish years ago, I just thought the guy was being a bit silly and surely it wasn't that bad, but having read this, I can understand why someone might feel that way. I almost had a continuity lockout moment a few times reading this, and I've read all the previous books.
So, I don't really know if I'm entirely sold on the creative direction Feist has decided to go down in this trilogy. I think I won't be entirely sure of that until after the next two books have come out. He'll have to sell me on the idea.
Having said all of this though, I do ultimately think A Darkness Returns is about as close to a perfect rendition of what Feist was going for in this book as I could realistically ever hope for. That's an important thing because I don't know if he's always been able to pull that off.
Firstly, the action sequences are generally pretty good. They're not the best Feist have ever produced, and that's one of the reasons why I've knocked a star off, but they are overall pretty good.
Secondly, the buildup was pretty good. I think when I wrote up my review for Master of Furies, my contention had been that it was like it'd had a lot of really good buildup but then was betrayed by a middling conclusion. That wasn't really the case here. The buildup was good and the ending was good.
I also feel like A Darkness Returns has done a much better job of being a direct continuation of the story of the previous trilogy than a lot of Feist's previous trilogies have been. At least with the Riftwar proper, it sometimes felt like each successive trilogy would be a new story that happened to be set in the same general world and occasionally had some of the same characters, even if it was nominally all connected by one overarching story. Here, there's much more direct continuity of the storyline.
This was actually to the point where I don't even know if this really needed to be split off into its own trilogy. I think it may have been fine to say this is the fourth book of the Firemane saga than to split it off into its own trilogy. Maybe there's some plot reason for this and I just haven't gotten to that bit yet, but most of the core conflict and core cast of this book has been carried over from the previous trilogy, so I think it would have been fine to just acknowledge this is a continuation of what came before. But this really is a point where I think this has done a lot better than a lot of Feist's previous work.
The flow on is that I think a lot of the character development here has been some of the best Feist has ever provided. This hasn't always been a given, either. I mean, a lot of this is just that the core cast of the previous trilogy is still, for the most part, the core cast here, but it's still a merit that I feel like needed to be acknowledged.
I mean, I don't think this book is flawless by any means. However, a lot of the problems with it, once you get passed the continuity lockout aspects, have kind of always been problems with Feist's works to varying degrees, and if they're the sort of things that'd turn you off a book, you probably won't have gotten this far anyway. I feel like a lot of the traditional Feist problems are also much lesser problems here, but admittedly my opinion that could change once I've reread this book a couple of times.
On the whole though, I do think this is probably as close to perfect as you can expect from Feist once you accept that any new reader will have to go read everything else he's ever written to fully grasp what's written here.