Hmmm, not sure what to make of this one.
First, this goes back to Knight of Flames timeline and gives us Freddy's POV, so there's a lot that's repeated. Pretty much the first and last quarter of the book, in fact, and I ended up skimming the bulk of those parts, looking only for new details. About the only new thing we learn during those parts is that Freddy's a bigger jerk than I originally thought he was. We get confirmation of his powers, which are more extensive than hinted at prior to this.
As for the new stuff in the middle, well... Freddy's a jerk and I prefer not to read POVs of jerks. Mikey's somewhat better, but he's been a victim for so long that he (and Freddy) actually deludes himself into believing he's left that behind even as he willingly becomes Freddy's literal plaything. Which brings me to the second thing.
Second, there's just no way to see Freddy and Mikey's relationship as anything other than D/s, which is a dynamic I don't enjoy. Just because Freddy thinks he's doing good by Mikey and Mikey's getting out of the ghetto doesn't erase that. Freddy might want to see themselves as equals for whatever reasons he needs to, but they're really not.
Plus, Freddy's just not that good of a guy. He's not a complete bastard, but he's barely one sidestep away from Kane - and even that's only until he succeeds in his plan to off dear old daddy, which I assume is the next book, and then he will be exactly like Kane. (Actually, I'd argue that he's worse than Kane, since at least Kane's victims know they're victims. Freddy's don't.) Morals and ethics mean nothing to this guy. Or to Mikey. So I guess they are perfect for each other in that respect, but they're certainly not a couple I'm rooting for or care about, and the insta-love here is just completely unbelievable given that Freddy's practically a sociopath.
Ok, I give Freddy credit for not violating Mikey's sexual consent (or so he claims). But since he violates consent in every single other respect with everyone around him, that credit doesn't get him very far. It gets him a crumb. A crumb ground into dust.
The good news is you don't actually have to read this book. The last two books made it perfectly plain that Freddy's manipulating Laurence and how, and that he's trying to line up Quentin to kill their dad. So this book ends at pretty much the same point as the previous book, just with a bit more info than we had before.
Two more little nitpicks:
Mikey's a drug dealer and a high school dropout who's never been outside San Diego. He's not going to measure distances by kilometers. This same thing happened with Laurence in the last book. We use feet and miles in the USA. There are various conversion charts and calculators available online. This sort of error shouldn't happen, and it pulled me out of the story both times.
And lastly, mailbox flags work the exact opposite of how they're used here. When you have outgoing mail, you raise the flag. When the mailman comes, he lowers the flag and leaves the incoming mail. If the flag is up, that means the mail hasn't been delivered yet, not that it has been.