A Nemesis

1. (chiefly Canada, US) An archenemy
2. (chiefly non-North American usage) A person or character who specifically brings about the downfall of another person or character.
3. The principle of retributive justice.
4. (usually in the singular, formal) A punishment or defeat that is deserved and cannot be avoided.
5. The polar opposite of a character.
6. A righteous infliction of retribution manifested by an appropriate agent.
7. proper noun https://en.wikipedia.org/wiki/Nemesis