Nemesis was the god of vengeance, giving judgments and punishments to those who did evil to others or had an undeserved wealth. It represented revenge and the consequences that had to come for each crime.
Nemesis never used her powers for her own affairs. His actions were aimed at maintaining the balance in human relations. It was he who dispersed happiness and misery. It was also his duty to maintain the balance of happiness and misery in the world.