I'm embarrassed to say this, but I was bored for most of the book. It took me nearly a week to read it - maybe some external events influenced my reading, making me disinterested after a few pages of reading. But no... I just wasn't feeling anything. 
 I was disappointed. I was expecting more. 
 The Percy Jackson and the Olympians seemed, to me, so much more mature, so much more interesting, so much more memorable. And I read those books five years ago. I don't think I'll remember a darned thing about The Heroes of Olympus, save for that cliffhanger at the end of The Mark of the Athena and Riordan's realisation that he wasn't finished with Nico. 
 The Heroes of Olympus became increasingly more commercial, cliched... Disney-fied. Suitable since it's US publisher is Disney-Hyperion. If there was any thought I had during my reading of The Blood of Olympus was that it could have worked so much better as a serialised animated television show. It has that humour built for such a thing. It has that whole physics-doesn't-exist thing (e.g., Nico, Reyna and Coach Hedge falling out of the sky with the boulder-like Athena Parthenos trailing behind/above them). 
 Urghhh. Ahhh. Hmmm. 
 No wonder why I've kept this series in our 'children's series' section at work instead of re-shelving in 'Young Adult' considering the characters' ages. Riordan's writing in this series, to me, doesn't seem to fit. Percy Jackson's books feel a lot more 'young adult'. The characters deserved a lot more. 
 Okay, Braiden, stop raging. Accept and move on. 
 (It also says something when I only really slowed down my reading for Nico's and Reyna's POVs.) 
 Yeah, nahhh. Time to re-read Percy and remember the great days that were.