Percy Jackson, Annabeth Chase, Piper McLean, Jason Grace, Leo Valdez, Hazel Levesque, Frank Zhang. Camp Half-Blood from Rick Riordan books. The Elementals are chosen for protect the gemstones of the five elements: Fire, Water, Earth, Air, and Magic. Felix: Guardian of Fire. Helen: Guardian of magic. Juliet: Guardian of Earth. Alex: Guardian of Air. Elementals' princip gods: Ignis, god of fire. Magicae, goddess of Magic. Terra, goddess of Earth. Caeri/Aele, god of air and sky. Aqua, god of Water.