A few spoilers if you haven't read through Kat's POV **** 
 Ah Daemon, Daemon, Daemon. Let's just say he never disappoints :) 
 So this book is actually three books in one Obsidian, Onyx, and Opal read through Daemon's point of view. 
 Let's start out with Obsidian. Of course if you read this book through Kat's POV you already know how big of an a-hole Daemon can be. It was definitely interesting seeing things through his eyes. The reasons behind his motives and how he feels is totally different from Kat's view of him. This book definitely gives you a new perspective into who he is. And of course his alien cockiness is extremely annoyingly sexy, not just in this book but throughout all of them ;). I absolutely love Kat's and his bickering. 
 Onyx 
 This was probably my least favorite book of the series told through both perspectives. In this book Daemon is trying to prove what he feels for Kat and new threats are introduced to all of them. Blake is also introduced in this book, which whom throws a monkey wrench in the entire Daemon and Kat situation. But my reason for this being my least favorite is how Kat acts throughout this book. The decisions she makes really tic you off! 
 And finally Opal. I really enjoyed this book through both perspectives. I'm always partial to the males version though, it definitely portrays them in a different light. Anyways again if you read this before then you know in this book Dawson is back and they are preparing to help him rescue Beth from the DOD. In this book you see a little more of Daemon's sweet side and how incredibly strong he feels for Kat. You also are introduced to some very heated moments between them. But ultimately it's Daemon's intensity towards everything he does and feels that makes this book amazing. And the end of this book most definitely has a lot of feels! 
 Overall I definitely recommend giving this book a read, especially if you enjoy reading through different POV's and even if not, still amazing.