Grand Unifying Guesses/Percy Jackson

Children of Ares

 * The Soldier

Children of Hermes

 * The Scout

Children of Hephaestus

 * The Demoman
 * Also the Pyro.

Children of Apollo

 * The Sniper

Children of Dionysus

 * Berry Punch

Children of Hades

 * The Medic

Children of Athena

 * The Engineer

Children of Aphrodite

 * The Pyro. She wears the mask at all times to keep her teammates from ogling her.