Soseh and her sister were artificially aged to adulthood by their father and subjected to numerous tests. Soseh rejected her father and ended up battling and killing her sister. She joined with the JSA and became a reserve member. She continued her war with the Council and was later joined by Wildcat (Ted Grant) and Black Canary in an attack on a Council stronghold in Austria. There they found one of the Ultra-Humanite's surrogate bodies, but the evil mastermind had already removed his brain, leaving the discarded remains behind. 
Nemesis later joined several other JSA reservists in aiding the team against the triple threat of Obsidian, Eclipso, and Mordru.  However, she still had problems dealing with her anger. She raided another Council base, this time on her own. When she got there she found that Black Adam had already slaughtered everyone there, including her father. He asked her to join the group of fighters he was organizing to take back his home of Kahndaq and she agreed. After helping take over Kahndaq, she entered into a physical relationship with Alex Montez, another member of Black Adam's team, who was using a black diamond and mystic tatoos to control the demon know as Eclipso. 
The rest of the JSA were alerted to Black Adam's coup and went into Kahndaq to confront him. The situation turned into a violent riot as the people of Kahndaq rose up against the JSA. Nemesis entered into the fight and slashed Hourman (Rick Tyler) across the stomach. Rick Tyler saved himself by switching places with his father, the Rex Tyler Hourman, who was located within a pocket of time. Nemesis went to attack Tyler but Alex Montez blasted her through the chest with a bolt of magic from the black diamond. It turned out that blood from Alex's wounds had weakened the power of the mystic tatoos. Eclipso then began to take control of Alex and used him to deliver the fatal blast to Nemesis. Distraught, Alex threw himself off the roof where the fight was taking place and landed next to Nemesis. The JSA recovered both bodies. 
- Eidetic Kinesthesia: Due to her father's experiments, Soseh could perfectly duplicate any fighting technique she encountered.
- Regeneration: Soseh will automatically heal from nearly any physical wound. The only way to kill her is either through severe head trauma or stopping her heart.
- Hand-to-Hand Combat (Advanced): Nemesis was an expert hand-to-hand combatant owing largely to her ability to duplicate any physical discipline.
- Swordsmanship: Nemesis was a deadly opponent with a sword and could wield two weapons simultaneously with equal efficiency and effectiveness. 
- Nemesis was one of many of the international heroes introduced during DC's "Planet DC" theme annuals of 2000.
- During the "Black Vengeance" storyline, Eclipso (Jean Loring) created a stone effigy of Nemesis and had it fight against Atom-Smasher and Stargirl. 
- 17 Appearances of Soseh Mykros (New Earth)
- 9 Images featuring Soseh Mykros (New Earth)
- Quotations by or about Soseh Mykros (New Earth)
- Character Gallery: Soseh Mykros (New Earth)
Justice Society of America member