|“||I enjoy tearing down the proud and powerful, and there are none who deserve tearing down like Gaea and her giants. Still, I must warn you that I will not suffer undeserved success. Good luck is a sham. The wheel of fortune is a Ponzi scheme. True success requires sacrifice.||”|
Nemesis (Greek: Νέμεσις) is the Greek goddess of balance, retribution, and vengeance. Her Roman counterpart is called Nemesis for revenge is universal, though she may also be considered Invidia. 
Nemesis was born from the protogenoi Nyx (Night) through parthenogenesis (by herself, therefore she’s a primordial goddess herself).
Story of Echo and Narcissus
Seeing the handsome hunter Narcissus treat his admirers with contempt, Nemesis lured him to a pool where he saw and fell in love with his own reflection, eventually withering away and dying from being unable to look away from his own beauty.
Nemesis is the mother of Ethan Nakamura. Ethan tells Percy who his mother was right before swearing allegiance to Kronos and supplying the last piece to revive him. He tells Percy that he lost his eye shortly after learning who his mother was, saying that he found out what the meaning of the proverb, "An eye for an eye" the hard way.
While Ethan joins Prometheus in a peaceful talk with Percy Jackson, he claims that he and his mother aren't respected. Percy calls Nemesis the goddess of revenge and wonders why she deserves respect, but Ethan tells him that she is also the goddess of balance as she causes the downfall of people with too much good luck. He also tells Percy that Nemesis took his eye as payment for he would one day bring respect to the minor gods. While Ethan saw an eye as a small price to pay, Percy doesn't see Nemesis as a loving mother for taking her child's eye.
Later, as Kronos starts to destroy the thrones of the gods in Olympus, Percy reminds Ethan that his mother was the goddess of balance and that total destruction isn't balance. This convinces Ethan to turn away from Kronos and attack the Titan Lord, but he is eventually killed when Kronos tosses him off Olympus for betraying him. However, just like Nemesis promised, Ethan was able to bring respect to the minor gods by giving Percy the inspiration to ask for this change to the gods as his wish instead. Nemesis is one of the gods to receive a cabin at Camp Half-Blood .
Nemesis appears in The Mark of Athena on the same island as Narcissus, Echo, and Narcissus's fan club. Leo and Hazel find her opening fortune cookies and changing the fortunes from optimistic to pessimistic (although she does leave alone the fortunes which she believes are enough). Leo initially perceives her as his Aunt Rosa, while Hazel sees her as her former teacher, Mrs. Leer; each is someone the demigod in question hated. Nemesis reveals that, after Leo bombed New Rome with the Argo II, the gods of Olympus blamed Herafor the budding civil war between the demigods, causing the goddess to flee from Olympus . Nemesis states that because of this, they can expect no help from Hera. Instead, Nemesis offers her aid to Leo and Hazel, as she considers it her duty to tear down the proud and powerful, and she counts Gaea and the giants as the worst of that category. She tells Hazel that she must save Nico by July 1 at the latest, and informs Leo that he will soon face a problem he cannot solve. Nemesis offers him her help, though she warns that it will come with a painful cost. She gives Leo a fortune cookie, stating that when he opens it, he will have the answer to his problem. With that, she sends the two demigods off to find Narcissus and Echo.
Later, in Rome, Leo finally breaks open his fortune cookie to find the code to unlocking an Archimedes Sphere (though Nemesis is apparently irritated that he used the cookie to find a code). Though he successfully activates the sphere and saves Frank and Hazel from the eidolons, Leo is wracked with guilt shortly after when Percy and Annabeth fall into Tartarus, believing that the loss of the two demigods was the price he had to pay for rescuing his two companions earlier. He then keeps Nemesis' word, telling her he will defeat Gaea and the giants as the rest of the Seven and Nico di Angelo set sail for the the House of Hades.
Nemesis is mentioned to be the mother of Damien White .
|“||Nemesis always pays her debts, good or evil.||”|
Overall, Nemesis appears to be both fair and intense. She enjoys tearing down the proud and powerful, making sure no man has too much good in his life to prevent hubris .
Nemesis is seen as a cold, cruel goddess whose ruthlessness isn't exempt from even her own children, as shown when she took her son's eye as part of their deal. However, she does have a strong sense of honor, as shown when she swore to her son that he would gain recognition from their deal.
Nemesis has short, curly black hair and golden eyes. She currently wears a red jacket, black jeans and boots, carries a whip and owns a motorcycle.
Nemesis will appear as someone the viewer wants to take revenge on. This means that she will always look different to different people. For example, when she met Leo, he thought she looked like Aunt Rosa. Even if the observer sees this person, Nemesis herself doesn't seem to know who she is perceived as.
- Tychokinesis: As the goddess of balance, retribution and vengeance, Nemesis has absolute and divine authority over luck. She will provide bad luck to anyone with too much good luck and good luck to anyone with too much bad luck.
- Destiny Deals: Nemesis can change someone’s destiny as long as she receives adequate payment in return. In exchange of his eye, she made her son Ethan change the war by reviving Kronos and making the demigods recognized as she promised.
- Curses: Nemesis can create horrible curses as punishments. She punished Narcissus in only loving himself.
- Umbrakinesis: As one of Nyx’s children, Nemesis can control and manipulate shadows. She displayed this ability by making the area around herself darker.
- A scale, the wheel of fortune, the rudder, balance and cubrit, the whip or sword.
Ethan Nakamura (deceased)
Nemesis never claimed Ethan as her son due to her lack of cabin, so Ethan end up getting stuck in the Hermes' Cabin , similar to what happened with many other demigods at Camp Half-Blood . One day, Nemesis met her son and promised that he would one day balance the world's power, in exchange for his left eye. Her son agreed, so she took his left eye and he wore an eye patch over it.
Her name's origins, "nemêsis" and "nemô", mean "dispenser of dues." The word "Nemesis" is now often used as a term to describe one's worst enemy, normally someone or something that is the exact opposite of oneself but is also somehow similar.
- In The Last Olympian , Nemesis's symbol is a set of scales, as seen on Ethan's burial shroud. In The Mark of Athena , Leo says a broken wheel is also her symbol, as it is in her cabin at Camp Half-Blood.
- It is odd that Ethan's burial shroud had scales under crossed swords when Nemesis is mainly pictured with a whip in one hand and scales in the other.
- A festival named after her called Nemeseia was held at Athens in Ancient Greece. It involved torch races.
- A statue of Nemesis or Themis is sometimes seen in courts of law to represent the balance of justice.
- The woman depicted on the New York state flag, holding the scales and sword, is believed to be based on Nemesis, Themis or Dike (the goddess of Moral Justice).
- On Rick Riordan's website, Nemesis is said to be sisters with the Roman form of Tyche, Fortuna. Whether this is true only for the series or if Riordan made a mistake is unknown.
- In Ancient Greek imagery, Nemesis is depicted as being winged, although she is yet to appear in such a form in the series.
- According to mythology, Zeus once fell madly in love with Nemesis, but she avoided his advances by turning into a goose.
- Other legends tell that as a result of her union with Zeus assuming the form of a swan while Nemesis was in the guise of a goose, she laid an egg from which Helen of Troy hatched.
- Her Roman name, Invidia, is Latin for Envy, one of the seven deadly sins.
- Her Norse equivalent is either Vidar or Forseti.
- Her Egyptian equivalent is Ma'at.