The Mark of Athena | By Rick Riordan | Characters

The protagonists in the story are Leo Valdez, Piper McLean, Jason Grace, Annabeth Chase, Percy Jackson, Hazel Levesque, and Frank Zhang. They are seven demigods that have been chosen to go on a quest to Gaea, and they face many dangers that can be life threatening.... DUN, DUN, DUN! The antagonist is Gaea and all of her children, which is most monsters (e.g. Giants, Ogres, Cyclopes, etc.), they are trying to stop the 7 demigods and make sure they don't prevent Gaea from awaking, which means that all humanity will be wiped out and only wild animals and Gaea's children will roam the earth.
defeat

Jason Grace -- Serious yet kind, great leader | Blonde hair, blue eyes, light skin | Son of Jupiter

Leo Valdez -- Very silly, sense of humor, good with machines, somewhat lonely | Brown hair, green eyes, tan | Son of Hephaestus

Piper McLean -- Kind, persuasive, protective | Brown hair, blue eyes, tan skin | Daughter of Aphrodite

Annabeth Chase -- Intelligent, kind | Blond curly hair, stormy grey eyes, light skin | Daughter of Athena

Percy Jackson -- Kind, protective of his friends | Brown hair, sea green eyes, light skin | Son of Poseidon

Hazel Levesque -- Secretive, kind | Curly brown hair, brown eyes, dark skin | Daughter of Pluto

Frank Zhang -- Kind, clumsy, sensitive | Brown hair (buzz cut), brown eyes, light skin | Son of Mars

Gaea -- Evil, deceptive, bloodthirsty | Earth (no physical description, she's just mother earth)

I have finished the book. :)

KF