Percy Jackson: Son of Chaos and Guardian of the Hunt

Annabeth cheats on percy with his half brother Nathan. Heartbroken he runs away from camp and goes to his moms place seeking comfort. Unable to go back and face the pain brought upon him he tries to live his life outside of camp. Though it is not as easy as you think. After a while he disappears from the face of the Earth, even the gods except a few don't know where he is. Then after 5 years he comes back with a few surprises and shocking news.