When I read Fae: The Wild Hunt by Graham Austin-King, I was under the impression I was reading a darker-than-normal fantasy which would still very much fall under the auspices of Young Adult fiction. Having read the sequel, I revised my opinion and now think of Graham Austin King as a grimdark author and a very good one. He doesn't lace his work down with profanity, sex scenes, or visceral violence but manages to invoke the kind of subtle horror as well as causal brutality which Mark Lawrence was a master of.
Fae: The Realm of Twilight picks up some months after the initial book ended. The invasion of Angland by the Bjornmen continues apace with a good portion now under the control of the invaders while the locals mount a brave but, ultimately, futile resistance against them. The Fae, however, continue their nightly attacks against the Anglish locals and have begun mounting attacks on the Bjornmen as well. Our heroes Devin and Kloss work against both the Fae as well as each other in their attempts to protect their loved ones.
This isn't where the chief tragedy of the book occurs, though, as Kloss' wife Ylsriss is kidnapped by the fae while trying to protect her child. This results in her being transported to the Twilight Realm where the Fae reside, her body and mind subjected to constant horrors as her captors work to break her. Much like in the Broken Empire Trilogy, the sexual assaults which are a part of this occur off-panel but the mind fills in the blanks. Readers who want nothing to do with such things should consider themselves forewarned.
The previous book suffered from some balance issues with the Bjornmen seeming to be a much greater threat than the Fae and not enough time devoted to fighting them. Indeed, I said I'd prefer to read about the conflict between the Anglish and Bjornmen than their struggle against the Fae. This book reverses my opinion as the Fae get some badly needed character development and while they remain a monstrous alien threat, you understand what has driven them to such extreme even as you want them destroyed.
Unsurprisingly, the Church of the New Days is revealed to be corrupt and in league with the Fae. This was foreshadowed heavily in the first book but spelled out here. I'm rather disappointed with this actually as I have difficulty believing the entirety of the Church would be corrupted as well as the secret left out. You'd think they'd be among those who would want to destroy the Fae as remnants of the pagan past even if only by sheer numbers. One of my favorite moments was where a believer in the new faith rejects the Fae Lord even in the face of his claims to be behind her religion. Good for her.
The Twilight Realm chapters are the most engaging of the book with lots of world-building. We also get insight's into the Fae's motivations, history, and culture. I also am weirdly happy to state the horrors inflicted upon humans are equal-opportunity as very few stories reflect that. Making the villains rapists is usually just a cheap way of making them hateable but here it's displayed from multiple angles without ever getting gratuitous. It's an act of power and domination through the lens of mind-control ala Jessica Jones.
My favorite character of the series, Selena, also gets her own subplot in an attempt to persuade a curiously-reticent monarch into engaging the Bjornmen. The reason for the king neglecting his duties could have been tied to the Fae but Graham Austin-King is smart enough to have a different answer for that.
In conclusion, I think this book is very good for those who like their fantasy grim and dark but more ethereal than gritty. This is a bit like a fairy tale without the whitewashing of the Brothers Grimm and it works well for that. I would, however, state this is something which should be reserved for more mature readers. At least fifteen or so.