User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-2.50.239.45-20130331135159/@comment-2079715-20130331142955

1. It is very likely that Jason,Frank, Hazel and Nico will have POVs in HoH. HoO5 is  unknown.

2. It is possible, we don't know much about it for now.

3. We will know about it through Piper's Katoptris or through dreams or some such.

4. Stoll brothers are still counselors of Hermes cabin. They will probably lead their house in battle against Romans.

5. Not likely.

6. Yes he will, and when he does, all the gods will probably join the battle against Gaea.

7. We don't know.

8. They are taking it to Athena,Greece, and after that, on Olympus.

9. Probably. That was the whole point of Mark of Athena.

10. It means that Nico suffered 5 days without air in a cup where Otis and Ephialtes imprisoned him.

11. If Michael Yew were alive, he would've probably make it known by now. Alas, I'm affraid he is dead.

And last, Percy is the most powerful demigod. Nico di Angelo said it in Mark of Athena, and lots of polls with fans were done, and in most of them Percy won.