Nemesis

Nemesis, (Νέμεσις in Ancient Greek) is the goddess of retribution and vengeance for arrogance, undeserved fortune, and vanity.

History
Nemesis is the daughter of the Titans Oceanus and Tethys. She appears chiefly as the avenger of crime and the punisher of hubris. Her name in Greek means "to give what is due", therefore giving her the nickname of Justice.

Percy Jackson and the Olympians
Although she was not seen in the series, she was mother to Ethan Nakamura and sided with Kronos when given the choice between siding with the Titans or the Olympians. She indirectly plays a major role in the series through her son as she made an exchange with him in order to bring respect to the minor gods. Although Ethan gave a much higher price than his required eye, the minor demigods and their parents were given their own cabins and general amnesty from Olympus.

Personality
Nemesis is a cold and even cruel goddess whose ruthlessness is not exempt from even her own children as shown when she took her son's eye as part of their pact. However, Nemesis does have a strong sense of honor as exemplified when she swore to her son that he would gain recognition from this same agreement. Overall, she seems to be fair and just.

Known Children

 * Ethan Nakamura (deceased)

Trivia

 * 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.
 * Nemesis is also called the goddess of balance, she makes sure no man has too much good in his life to prevent hubris.
 * Her symbol is a set of scales.
 * On Rick Riordan's website, Nemesis is said to be sisters with the Roman form of Tyche, Fortuna. Whether this is true to the series or if Rick Riordan made a mistake is unknown.
 * She is always pictured with a whip in one hand and scales in the other.