Luke Castellan is a 19–23-year-old demigod, the son of Hermes and May Castellan. Introduced as the friendly head counselor of the Hermes cabin in The Lightning Thief, he is soon revealed as an antagonist and a servant of Kronos. Luke held a grudge against the gods after his father didn't help him when his mother took fits because she could see his future after trying to become the oracle but was driven insane in the process. After running away from home at age nine, he arrived in Camp Half-Blood with Annabeth, Thalia, and Grover. Subsequently, he stole Zeus's master thunderbolt, poisoned Thalia in her tree form in The Sea of Monsters, and kidnapped Annabeth in The Titan's Curse.
Near the end of The Battle of the Labyrinth, Luke bathed in the Styx, obtaining the curse of Achilles, in order to host the spirit of Kronos. He changed back into his own self for a moment after Rachel Elizabeth Dare hit him (possessed by Kronos) with a plastic blue hairbrush. Kronos used Luke's body in the war against the Olympians, but Luke redeemed himself by stabbing his a spot near his armpit on his left arm (his weak spot), destroying himself and Kronos. He turns out to be the hero of the prophecy because of this. The last three lines in the prophecy refer to him, Percy, and Annabeth's dagger. Luke is the hero, the single choice is made by Percy, by giving Luke Annabeth's dagger, which is the cursed blade. The weapon is cursed because Luke broke his promise to Annabeth and Thalia, that they would be a family, as Luke was the one who gave Annabeth her dagger. As he died, Luke explained to Percy the sadness he felt for all the kids who ended up in his father's cabin because they were unclaimed, which inspired Camp Half-Blood's later recognition of minor gods and having the gods claim their children at the age of thirteen.
Luke is described as handsome, with sandy hair, blue eyes (gold when possessed by Kronos), and a long scar on his cheek given to him by Ladon the Dragon, while trying to steal a golden apple from the Garden of Hesperides; a quest offered to him by Hermes, which he failed.
Near the end of The Battle of the Labyrinth, Luke bathed in the Styx, obtaining the curse of Achilles, in order to host the spirit of Kronos. He changed back into his own self for a moment after Rachel Elizabeth Dare hit him (possessed by Kronos) with a plastic blue hairbrush. Kronos used Luke's body in the war against the Olympians, but Luke redeemed himself by stabbing his a spot near his armpit on his left arm (his weak spot), destroying himself and Kronos. He turns out to be the hero of the prophecy because of this. The last three lines in the prophecy refer to him, Percy, and Annabeth's dagger. Luke is the hero, the single choice is made by Percy, by giving Luke Annabeth's dagger, which is the cursed blade. The weapon is cursed because Luke broke his promise to Annabeth and Thalia, that they would be a family, as Luke was the one who gave Annabeth her dagger. As he died, Luke explained to Percy the sadness he felt for all the kids who ended up in his father's cabin because they were unclaimed, which inspired Camp Half-Blood's later recognition of minor gods and having the gods claim their children at the age of thirteen.
Luke is described as handsome, with sandy hair, blue eyes (gold when possessed by Kronos), and a long scar on his cheek given to him by Ladon the Dragon, while trying to steal a golden apple from the Garden of Hesperides; a quest offered to him by Hermes, which he failed.
In the movies, Jake Abel plays the part for Luke Castallen.