User blog comment:Hermione Chase/"The Blood of Olympus" Expectations/@comment-24477935-20140128144337

I just noticed, many are giving too much credit to Percy for being able to control poison. It was interesting to see his dark side, but truthfully, I think poison control is only possible in Tartarus (unless you're a demigod child of Akhlys)

From HoH:

"It was a crazy idea. Poseidon was god of the sea, not of every liquid everywhere .  Then again, Tartarus had its own rules. Fire was drinkable. The ground was the body of a dark god. The air was acid, and demigods can be turned to smoky corpses.

So why not try? He had nothing left to lose."

Here's my theory:

 I think it may be the influence of Tartarus (or the arai - spirits of curses) that made Percy have power over poison. They want Percy to feel what "real power" looks like. Maybe Tartarus brings out the worst in you and your abilities. If Jason were in Tartarus, maybe he could control and remove the air in the lungs of his enemies. If Frank were there, maybe he could transform to monsters and other humans as well. I have other examples, but you get my point.

 Annabeth on the other hand, has no special abilities. Her most important weapon is her mind and maybe that's the reason why Tartarus didn't get to give her evil thoughts. What do you think?

