This is a tough book to review for many reasons, but the biggest problem is not knowing whether or not this is going to be a series. Based on the story, I'm assuming there will be other books but it seems as though there is so news for a sequel. In any case, this review is written thinking there are going to be more books. 
 AN EMBER IN THE ASHES is clearly very well-thought-out. The story is complex and has multiple layers of depth that all contribute to making the world what it is-and what a wonderful world it is. And let's make it clear I'm talking about world building here, because the actual world is far from wonderful. It is a gritty, no holds barred, brutal world the characters live in, and I appreciated that the plot reflected that, even if a few things made me uncomfortable. (view spoiler)[Rape is not uncommon in this world, and it is somewhat frequently brought up. (hide spoiler)] 
 Speaking of the world and plot, I really liked the backstory and detail given, although there could be a bit more explanation on why things they way they are, the workings of the main setting of Blackcliff Academy is well defined. This is a world and story that has huge potential, which is all the more shame if this does not turn out to be a series. So much is built up for multiple books and if this really is a standalone I don't get it. 
 The characters were great; Elias and Laia were well fleshed out, but I did have a hard time really caring for Laia so I felt somewhat of a disconnect to the story. There is a wide variety of side characters, each with different personalities and goals, but I think everyone needed a bit more character development, there didn't seem to be a lot of growth, in my opinion. 
 AN EMBER IN THE ASHES takes somewhat of a different approach to romance, where Elias and Laia each have their own love interest from their current lives before the two cross paths. Some have been calling this a love square but I don't think this is really the case. At least, I didn't mind it or find it annoying at all. The romance does not take center stage anyway, because there are much bigger things to worry about. 
 It seemed like more time was spent on trivial things like roaming around Blackcliff and daily chores than the big plot events. (view spoiler)[The Trials went by way too fast! (hide spoiler)] But when stuff was going down, it was pretty damn awesome, I was like heck yes I'm totally in this is so great! 
 All in all, I liked the book. I would definitely recommend it despite some of the issues I had, and would love to see a sequel.