|“||Deserve better... if only they just... had thrones—||”|
–Ethan to Percy Jackson with his dying breath, in The Last Olympian
Ethan Nakamura was a Greek demigod, a son of Nemesis, the minor goddess of balance, retribution, and revenge. He joined the Titan Army in the Second Olympian War but was killed after his betrayal of Kronos during the Battle of Manhattan.
Ethan grew up like most demigods. When he was old enough he was brought to Camp Half-Blood by an unknown Satyr. As his mother never claimed him, he was stuck in the Hermes cabin, similar to what happened with many other demigods at Camp Half-Blood. Like most demigods that turned to Kronos' side, the fact that he remained unclaimed and unrecognized by the other members of Camp Half-Blood. Enraged, Ethan eventually joined the Titans.
He met his mother Nemesis one day, and she promised that he would one day balance the world's power, in exchange for his left eye. She took his left eye and he wore an eye patch over it. In the series, he later recounted this story to Percy Jackson, whose response was sarcastically praising his mom. Other than this, it is assumed Ethan and his mother never met again. It is unknown if Nemesis removed his eye or simply blinded it.
Ethan fought Percy Jackson in Antaeus' Arena to prove himself, as it was the only way to join Kronos' army. However, due to Ethan's heavy armor, Percy deliberately fought to tire him out, and therefore he lost to Percy. He seemed to accept his fate and told Percy to "get on with it" and kill him. But Percy refused to kill him and helped him up instead. When Percy killed Antaeus, Ethan escaped the Arena along with Percy, Annabeth Chase, and Rachel Elizabeth Dare.
After escaping and telling the others his story, Ethan ran off on his own, declining their help.
Ethan is later seen with two telekhines, discussing their plan to resurrect Kronos. Percy, who was wearing Annabeth's magical Yankees cap to be invisible, took it off and begged Ethan not to resurrect Kronos. Percy had spared him, but Ethan betrayed him, and by joining Kronos' cause, he raised the fully restored Titan Lord from the depths of Tartarus. He is the traitor mentioned by the Oracle of Delphi in the prophecy that the Oracle gave in the beginning of the book.
Ethan, with the assistance of the titan Iapetus (later becoming Bob), stole the unfinished Sword of Hades with the intention of using it to resurrect many of the Titans from Tartarus. After Iapetus fell into the River Lethe and the sword was retrieved, Ethan fled.
Ethan is a lieutenant of Kronos. He enters battle, led by Kronos, and almost kills Percy with a poisoned knife, almost stabbing him in his "Achilles' heel," or weak spot, but Annabeth manages to get in the way, and he stabs her instead therefore saving Percy. Percy is furious and hits Ethan on the helmet with his sword, denting his helmet and knocking Ethan unconscious.
When confronted by Kronos about where exactly he was aiming when facing Percy in battle, he tries to imitate the attack. He simply claimed that he was not aiming for any place in particular and it was all a blur to him. It is possible one of the gods, most likely Nemesis, was acting through Ethan because he or she felt that Percy Jackson should be torn down due to his invulnerability, or that the blow to his head by Percy caused Ethan to suffer some short-term memory loss (a common side effect of a concussion) and he forgot about the spot, or he might have just aimed blindly.
During their last showdown, while Kronos is destroying the Olympian Throne Room and the gods' thrones, Percy pleads with Ethan that Kronos is evil and that destroying everything would not bring about balance, which Ethan being a son of Nemesis is trying to achieve.
Ethan rebels against Kronos at the last second, saving Percy's life. Ethan strikes Kronos' neck, but the blade shatters instead, one piece ricocheting through his armor into his stomach. Ethan tells Percy, with his dying breath, that the minor gods, like his mother Nemesis, deserve thrones and appeasement or forgiveness from the rest of the gods as they've been treated lowly. Kronos then causes him to die by making a fissure in Olympus. Ethan falls into empty air, thousands of feet above the ground. This makes Ethan the last person to be killed by Kronos.
Percy made Ethan a shroud after the battle, choosing to remember him for his good deeds rather than his evil ones. His shroud is black silk with swords crossed under a set of scales, the symbol of Nemesis. To respect Ethan's dying wish, Percy uses his gift from the gods to have them swear on the River Styx that they will honor and claim all the children of all of the gods by the time they turn thirteen, and honor the minor gods themselves by putting cabins in Camp Half-Blood and thrones on Olympus.
Ethan is a good fighter, a brave and strong boy. He is considered untrustworthy, as he betrayed Percy, and in The Last Olympian switched sides again and attacked Kronos. Ethan is considered to be very driven by his goals. Knowing that he will one day bring balance, he follows this goal and tried to achieve it the best way he can, even if it means betraying those he has allied with. Ethan also has a strong urge to bring balance to things, feeling that the minor gods deserve more respect and eventually paying Percy back for saving his life by attacking Kronos, getting killed in the process.
Percy stated that Ethan is an Asian boy around sixteen with glossy black hair and a slim, wiry build. His Greek armor hung off of him slightly when he was wearing it (showing that it was too big, likely because of Ethan's slim build). His most recognizable feature is the black eye patch over his left eye. In The Last Olympian, Percy squashed his nose with Riptide. It was said to look "like a squashed tomato." It is not clear whether his mother, Nemesis, completely removed his eye or simply blinded it.
- Swordsmanship - Ethan is an extremely skilled swordsman, despite the lack of one eye. Ethan's fighting style, especially in the arena, revolves mostly around defense. This allowed him to hold his own against even Percy Jackson in The Battle of the Labyrinth (a demigod who could defeat entire cabins at a time in sparring), but causes him to tire quickly if forced on the offensive, which caused him to eventually lose to Percy.
- Ethan's surname Nakamura is a Japanese name that means "middle village."
- 'Ethan' means "strong", so Ethan's entire name would be "strong village."
- Ethan gave up his eye to his mother as an offering to her because he was told he could create balance by doing so.
- His first name means "strong, firm, and impetuous." We see him being strong and firm during a duel despite lacking one eye. At the same time, he acts impetuously by attacking Kronos (in Luke's body) from behind, forgetting Luke's Achilles' Curse.
- In The Mark of Athena, Nemesis tells Leo that she recently received an eye for her help. This could be a reference to Ethan, who sacrificed an eye to his mother for her help.
- Ethan appeared in the film adaptation of The Sea of Monsters, played by Danny Le Boyer.
- Ethan, Drew Tanaka and Alice Miyazawa are the only known demigods of Japanese descent.