*Spoilers Ahead*
This was a well written book, but I did not enjoy pushing my way through it. Almost the entire second half of the book the main character spends being tortured in an attempt to break him, until they finally do to an extent. Ember and Max are basically drafted as citizens into the kingdom they get pulled into, and neither of them seem to have an issue with it. They travel with an archwizrd, who has to be the lamest archwizrd I've ever read about, and his daughter who are trying to kill the man they both care so much about. Later on in the story Ember becomes the abduction target of basically every other nation and criminal organization in the book for who she is, but that plot thread is left hanging for the following book.
There is so much about this book that is dark and depressing (yeah I know, the title kind of gives it away), but there are few points of levity to counter balance this darkness. These points of levity are limited to casual and less-than-casual flirting between characters, but even these are highlighted by the nastiness that is happening around them. Darkness in a story is fine. In fact I enjoy a good amount of it when I am reading a book as it helps to give the story a sense of gravitas and provides something for the characters to push through. However, when this darkness is not countered by light or levity it starts to lose it's impact, and I feel like I am slogging through one depressing scene after another.
What makes the horrible things that characters go through feel so potent to me is how it contrasts with the happy times that they experience. The happiness for Kael, Ember, and Max is the world that they come from, as it is referenced multiple times throughout the book how dark and evil the new world they were pulled to is. However, even the happy memories from their world are seeped in darkness as the one chapter they get there focuses heavily on how Kael and Ember were mugged in past which leaves Kael with a useless arm, a limp, and is constantly in pain.
An example of a dark story that closely matches the tone for this one, but uses levity well to break up the monotony is the first Dresden Files book, Storm Front. That book is filled with dark imagery, brutal assaults, and various other elements that hit the noir setting on the head just as The Legacy does. However, Storm Front has Bob in it. A sarcastic and wise cracking skull who is briefly in the book for portions of only two or three chapters. That isn't much, but it pulls the veil of darkness back enough so that the reader can smile at the situation and know that there is more than just the awful things that keep happening.
In The Legacy I found that what happens to Kael's not-quite-vampire friend was a let down. She ends up being killed right in front of his eyes (I warned you about spoilers didn't I?) which is what ultimately led the witches' partial success in breaking his resolve not to kill. However, it is revealed at the end of the book that she did not die. She curses the witches for fools about how silver won't kill her, but rather just waken the demon within (hinting that she is now a full vampire). That not only leaves the Dead Witches looking like a bunch of fools who don't understand the monsters of this world thus diminishing how seriously they can be taken, but also leaves a potential plot hole of if all the not-quite-vampires need to do to awaken their demon is to kill themselves with silver, why aren't there more?
One last complaint about the book is the dialogue. I can't quite put my finger on it, but it feels off throughout the entire story. Some points feel stunted, some feel unnecessarily long, some feel like an entire conversation is being had in the middle of a very tense moment. I wouldn't necessarily say that it is bad throughout, but it could certainly have been better.