Percy Manipulates Fire

"Percy gave a battle cry. At the Cyclopes’ feet, a red vein in the ground burst open, spraying the monsters with liquid fire from the Phlegethon. The firewater might have healed mortals, but it didn’t do the Cyclopes any favors. They combusted in a tidal wave of heat. The burst vein sealed itself, but nothing remained of the monsters except a row of scorch marks.
'Annabeth, you have to go!' Percy said. 'We can’t both stay!'

- House of Hades, Chapter LXX (Annabeth), Pg. 377