** spoiler alert ** 
 Fantastic way to end the series! Nico PoVs! Thank you Rick Riordan for those, as Nico is my favourite character besides Leo. And Leo, Oh Leo! I love what happened. on a stupid phone, so I'll post a more coherent spoiler protected review once I get to my laptop. I'm so excited! I literally devoured this book in about 3 hours. 
 Edit: I hope we get some short stories out of this, or even a miniseries. I could totally get behind a Leo/Calypso series, and I really want to see if Nico and Will do get together as a couple. 
 Reyna was also awesome, and I like how this book focused more on her and Nico, rather than the actual seven. Yes, there were some Piper/Jason/Leo chapters, but I did like how we got to see Reyna and Nico work together. 
 Octavian, it sounds horrible, but I'm glad he's gone, and I'm not surprised his madness did him in, and his own men turned on him. It's a trend with crazy ass Roman emperors and he practically declared himself one. 
 Apollo, I feel bad for him. He's an idiot (and was in the Percy Jackson books too), but Zeus is an even bigger asshole. I don't think Apollo should be punished, because this was not all his fault, it was a problem equally created among all the Gods, because Zeus and the others only half fulfilled their promises, and only did so gurdgingly. 
 Fantastic series, I'm so glad I re-read Percy Jackson, and the previous Heroes books leading up to this. I'm still too excited trying to digest what I've read and get my thoughts in order, hence the rambling.