Let me start out by saying that this is going to be a ridiculously long review and it's going to be unusual in that I'm basically reviewing the YA Age of Legends trilogy in comparison and contrast to Kelley Armstrong's adult Cainsville series. It's more of my own analysis than a review. As someone who has read almost every Kelley Armstrong novel out there and who has been a huge fan ever since Bitten, I could not for the life of me read Age of Legends without assessing it through the prism of Cainsville. This is not necessarily a bad thing although it does mean that this review will probably be of limited value unless you've read both. THERE WILL BE SPOILERS FOR BOTH SERIES. Also, if you love one and haven't read the other, suffice to say that I'm pretty sure you'll love the other so go read it. 
 First of all, a disclaimer: I have been an obsessed fan of Armstrong's Cainsville novels ever since Visions, the second book, came out. Part of that is because I was going through a tough hospital internship and I used the August 2015 publication date of Deceptions (3rd book) as basically something to look forward to when I'd feel like crap. I know it sounds a little crazy - what does a book have to do with a medical internship? - but sometimes you just have to assign these weird rewards for yourself. Use whatever works when you're depressed about how overwhelmed you are and wondering if it'll ever get better. BUT, even if I hadn't made Armstrong's writing into a carrot, I would have always loved the Cainsville series just for the characters. 
 For the sake of not making this into a five page essay, I'm just going to assume that you have knowledge of both series. Which finally brings be back to the Age of Legends, because the similarities in characterization are there and they're pretty undeniable, to the extent that sometimes it flat out felt weird to read about Gabriel's mannerisms and reactions from a character named, well, Gavril. I'm talking about some serious deja vu, because obviously Armstrong was writing this trilogy concurrently with her Cainsville novels and it shows in certain almost word for word descriptions. An quick example that comes to mind is when the female leads have a gun/dagger while being attacked but both stashed it so that it was unavailable; the narration of the realization and chagrin is basically identical. I'll briefly go over some of those characterization similarities (it'll all be the tip of the iceberg) before going into a possible rant about just how much it unnerved me even as I enjoyed it. 
 So we have this almost-not-really triangle between Gabriel, Ricky, and Olivia in Cainsville. Olivia is in a happy, more or less fulfilled sexual relationship with Ricky, who is the son of the head of this powerful Chicago biker gang. Ricky is honorable, confident, supportive, and just generally a pretty awesome guy. He knows what he wants and isn't afraid to go for it, but he's conflicted over his role in life as the eventual inheritor of the empire his dad is leaving to him. The drawback to being with him is precisely also part of his appeal: his sense of duty and loyalty to the gang sometimes conflicts with what he wants to do for Olivia. He has a great relationship with his father but the defining conflict in his life right now is based on how he's loyal to his father even though he recognizes that his dad is sometimes acting as a dad and sometimes acting as a leader. 
 Ricky's counterpart in Age of Legends is Tyrus, the bastard son of the emperor, destined for life as a prince and leader. Pretty much everything I wrote above about Ricky also applies to Tyrus. Again, the defining struggle for his character is the fine balance between fulfilling the Emperor's expectations and being able to find happiness and peace as a son who loves and admires his dad. 
 So now, Gabriel/Gavril. Oh my god, I don't even know how to start on this - there are huge differences, especially considering Gavril is a dark skinned and green-eyed teenage fighter of the warrior caste, and Gabriel is a early 30's (late 20s?) attorney whose natural environment involves suits, not swords. But both basically got put through horrible childhoods where they had a serious lack of parental love, learned to rely on themselves, and especially did not form emotional attachments to others. So we end up with two characters who are awkward at best in relationships with others, oblivious to social cues, who suck at offering comfort (hugging Gabriel is like a statue and Gavril is a wooden board), who are sympathetic and admirable, but also deeply flawed. They are struggling to be good despite what shaped them. For each, there just happens to be that one woman who gets under his skin...someone who might be interested romantically, but is already involved with someone else who is much more suitable and adept at actual relationships. 
 I'm not deliberately avoiding an analysis of Moria/Olivia (and Ashyn) although I do focus a lot on the male characters because for me, Moria and Ashyn are more or less different aspects of Olivia's character. Moria has Olivia's headstrong recklessness, unabashed physical enjoyment of the world, and the part that rejects society's focus on decorum and appearances despite their celebrity-like social status. Ashyn has her desire for quiet contentment, her love of books and learning (Olivia's fondness for Sir Arthur Conan Doyle), and her ultimate humble view of herself as an ordinary person in extraordinary times. All three of them lose their fathers and mourn, Moria/Olivia also step up to comfort, support, and protect Gavril/Gabriel through their mothers' deaths. That was a really awkward and confusing sentence to write, but you get the point. 
 Last of all, the two men in both series have complicated friendships with each other - which, thank goodness, is what raises these relationships from eyerolling, cliche love triangles to something more sincere and meaningful, in my opinion. Tyrus and Gavril were childhood friends and sparring partners, connected through their fathers' friendships. There is the same dynamic of: Tyrus is afraid to go after Moria at first because he thinks Gavril might have a prior claim on her affections. Likewise, Gabriel and Ricky are connected through Ricky's dad, who warns Ricky against pursuing a relationship with Olivia at first because of the potential Gabriel/Olivia relationship and basically the honor code of not going after someone else's woman. Ricky is basically Gabriel's only real friend outside of Olivia and Tyrus is basically Gavril's only real friend outside of Moria(/Ashyn). 
 Keep in mind that all this takes place in vastly different worlds and storylines, although there are some surface similarities in how Moria/Ashyn are connected to the spiritual world, while Olivia sees omens and visions. It was hard not to feel like the Age of Legends characters weren't teenaged, "-lite" versions of Gabriel, Ricky, and Olivia from Cainsville, but the series themselves are not as alike as all these comparisons might make them sound. I do think that if you're a big fan of the characters from one series, you should definitely read the other. 
 So, what was so unnerving about reading Age of Legends? Well, while the romantic relationships are an important part of both series but not the main priority in either, it turns out that I am totally biased and have my favorites. I've been waiting through three books as Gabriel sloooooowly comes to the realization that he actually has feelings for Olivia and should make a move - meanwhile, Olivia is solidly with Ricky, a great guy and a character I actually like a lot even though he's the "other" guy in this triangle. This is the equivalent of sitting through, what, four seasons of X-Files while being sure there should be something more going on between Scully and Mulder but also being a little afraid of whether a focus on that would ruin the partnership, friendship, and general relationship they've already developed. 
 So basically in the Cainsville series, I vastly prefer Gabriel over Ricky and I'm fairly certain that that's eventually going to be the main pairing, unless Olivia just ends up alone. But in Age of Legends, I am 100% a Tyrus fan. Which was really weird to me because, you know, he's the Ricky of this series. So basically the entire time I was reading Forest of Ruin, I sort of expected there to be a turnaround where Moria ends up with Gavril - it's certainly hinted at more than once that they might have deeper feelings for each other, plus Gavril was a main protagonist of the first book and YA series tend to stick to the "first love" concept an awful lot of the time. 
 I'm happy to say that Armstrong did not do what I expected but at the same time, it makes me a little worried for the future of Cainsville, you know? What if Olivia actually just never explored anything with Gabriel because Gabriel, being as stubborn and insanely in denial as he is, totally let that ship sail? This is exactly why I tend to hate love triangles, but one of the things I admire about this author is that she makes them feel realistic and her female characters don't just bounce aimlessly back and forth, basically becoming disloyal to both. Also, the romance and romantic issues are almost always secondary to the actual good story. 
 On a long side note, Armstrong has never let me down with the resolution of the relationships between characters. There was another trilogy of hers, the Darkness Rising trilogy, where I never liked the guy that was the love interest in the first two books and while I liked another character much more and thought they were suited together better, there wasn't a triangle per say since Armstrong's female characters don't do that stuff. As I once read some where, if you don't know who you love and would choose, you don't love either of them enough. But I was pretty much resigned to the pairing because it's YA, right? No way an author would have the temerity to NOT have her end up with the "original" guy. Amazingly enough, she defied the conventions and cliches. 
 So after all of that, the actual review of Forest of Ruin is quite simple: it's a satisfying conclusion in every way. I was a little concerned when I read Sea of Shadows because I thought it was good, but not excellent, but with each book the stakes have only risen and I grew to love the world that they're in. I grew up watching Chinese period dramas (some wuxia too) where the Emperor's many sons did indeed try to kill each other, where the concubines/wives/Empress maneuvered themselves into positions of power, and where gods, goddesses, and magic was thrown in along with the martial arts. Reading Age of Legends made me feel as if Armstrong had grown up watching the same things - which makes me insanely curious as to what she researched for the book and what inspired her. Forest of Ruin felt like an "older" YA novel in the execution of its ideas and the complexity of the world, one that very well could have been an adult fantasy trilogy. You don't get your usual all-good or all-bad characters, but rather the thing that I see as being the hallmark of a bildungsroman novel: the realization that the world is complicated and people are complicated. The exploration of concepts like honor/disgrace, the caste system, filial piety, and duty are what sets Age of Legends apart from the countless fantasy YA novels out there. One tiny example: the moment when Moria learns that Tyrus can't just show off a dragon to the general public, even if it's considered a sign of being blessed by the goddess, because in doing so, he would usurp the image of the Emperor. That is the kind of small detail that 95% of the YA novels out there would never be able to achieve - the kind of real world understanding of societal appearances (and the need for them, for better or worse) that escapes a child, but is grasped by an adult. 
 Sadly, I feel like this is what YA novels usually lack these days - and if that complexity is there, it's usually unpopular. In your typical YA novel, the whole concept of duty is an afterthought. I can't list how many novels I've read with princess characters who literally abandon their position because Truuuuue Loooooove (cough The Kiss of Deception cough) or because they don't like what they get in life. The romantic relationship comes before everything, even one's responsibility towards one's family, one's people, one's country. Worst of all, the readers most guilty of loving these types of characters are the ones who I think would most benefit from reading something a tiny bit more challenging. 
 But, after all, that's why I'm such a fan of Kelley Armstrong. Her idea of strong, realistic protagonists - whether female or male - meshes well with my values and beliefs. Spare me the narcissistic brats and show me people who are willing to sacrifice what they most want for the greater good, or for the good of others.