In short: The final book in the Wicked Lovely series, Darkest Mercy by Melissa Marr, is a satisfying finale and the most action-packed and intense book yet. Keenan becomes more tolerable. 
 Darkest Mercy was a truly satisfying finale to an involved series. It had tons of interesting plot developments and twists that made reading very quick and easy. It was definitely the most action-packed and fast paced of the series yet which was refreshing because one of my main complaints from the previous books in the series was that there was a lot of talk about the end of the world but very little action to back it up. The main drama of the previous reads was focused on the relationships. In Darkest Mercy, we get both relationship drama and action to create a truly intense read. 
 In Darkest Mercy, the reader gets to read from the point of view of a record total of eight different characters, including three that we hadn't heard from before in the previous books. This brings the total number of unique character point of views to fourteen! Quite a feat, especially because I never got confused or had difficulty distinguishing between so many different voices. If you're interested, here is the breakdown of the characters featured in each of the books (may be spoilery so highlight to read): 
 Wicked Lovely: Aislinn, Keenan, Donia 
 Ink Exchange: Leslie, Niall, Irial 
 Fragile Eternity: Aislinn, Seth, Donia, Sorcha 
 Radiant Shadows: Ani, Devlin, Rae 
 Darkest Mercy: Aislinn, Seth, Keenan, Donia, Niall, Far Dorcha, Gabriel, Chela 
 I'm still left with quite a few questions about faery mythology after Darkest Mercy. I'm the kind of person who likes tons of details and world building in everything I read so I was a bit disappointed that I still had a lot unanswered at the end. If you're not one of these people who is so obsessively involved in knowing every little detail about the mythology in a book then this probably won't bother you. 
 The characters in the Wicked Lovely series were ones that I had a hard time relating to. I almost feel like they were too "cool" for me with their multiple piercings, tattoos, motorbikes, and cigarettes. I'm just a simple nerd, a square really. And yet, I found that I really came to care for and love (almost) all of them. I'm probably going to miss Seth and his quirked eyebrow the most. He's a very easy character to love. And I don't think I mentioned this earlier but he lives in a train house! I mean, how cool is that?! I wish I lived in a train house. 
 And of course, I wouldn't be able to write a review for a book in this series without mentioning Keenan. In previous reviews, I've made sure everyone knew my loathing for him, calling him a plethora of things, including fake, manipulative, selfish, a prick, and a dick. He is able to redeem himself in Darkest Mercy which leads me to sympathize with his character a bit more than in the previous books but I have to say, I still dislike him on a whole. When faced with the decision between his court or his true love, there is only one clear choice that he could've made to make me like him and he took way too long to settle on it.