Disclaimer

When Percy was just a baby, his mother was murdered, leaving him in the care of his godfather, Nicholas Fury. From a young age, he was trained to fight so he could defend himself if he was targeted because of his relation to the highest ranking agents in Shield.

At the age of nine, he went on his first unofficial mission. He went undercover to take down a human trafficking ring. From there, he quickly established a reputation as Thanatos, the most ruthless and skilled assassin, rivaled only by the elusive Winter Soldier.

At age twelve, he was found at Yancy Academy, where he had been sent to live a normal life. Ironic, really. He learned he was a demigod and was sent on a quest with his two friends: Grover and Luke.