I'm so concerned about this book that I can't even properly understand how this happened. How did Rick's editorial team let this be published like this is beyond me. 

First of all I need to get this out of the way: I know I'm not the target audience for this anymore. But I read the Apollo series just last year and enjoyed it fine so the blame can't only fall to that. 

The writing style is redundant and soppy, far from the charming voice the entire universe has. Even if the other structural problems stayed, I still think a decent prose could've saved this book to be at least fun instead of a total drag, since there are a lot of elements that had potential. 

There are also several pacing, characterization and plot problems:
 • Nico is completely another person.
 • I can barely understand why or how these two love eachother because in a full year they don't even know basic stuff about one another.
 • Will is extremely one note.
 • Nico is portrayed as the person who is grieving Jason the most besides Piper.
 • They're trying *really* hard to get cookie points for representation instead of just... letting the representation represent (although I can understand the importance of spelling it out these things in MG books because it might be the first contact with the idea, it was too heavy handed.)
 • It had warnings, in caps lock, about every DREAM SEQUENCE. Every. Time. It ruined the flow and the mistery vibe of the dreams. (Also. They dream so much??? Asleep all the time. Lazy ass way for exposition.)

 • There are way too many explicit pop culture references that will age like milk (NICO MAKES A JOKE ABOUT LIL NAS X GOING TO HELL)
 • and, somehow, they let, I swear to god, Nico say Percabeth on page. 

My annoyance aside, I still had a really hard time understanding the story here. Bringing Bob back is the most coward backtrack ever, as much as I love him. The villain has no motivation, not even taking over the world. This is character-focused while refusing to go deeper on issues, making it the most sanitized installment in the universe. The "plot-twist" in the end doesn't really explains anything. 

Overall, very disappointed, because Nico was easily the most interesting and complex character Rick Riordan ever created and he deserved better. 

(I have a strong inkling Mark Oshiro was part of the fandom, was a fanfic writer at some point, and did not reread the books to write this)