What is the meaning of Nemesis?

An enemy, especially an archenemy.

A person or character who specifically brings about the downfall of another person or character, as an agent of that character's fate or destiny, especially within a narrative.

The personification of the "fatal flaw" of a dramatic hero in the style of Greek tragedy.

Polar opposite, especially of a literary character.

The principle of retributive justice.

A punishment or defeat that is deserved and cannot be avoided; (an instance of) retribution.

nemesis

Source: wiktionary.org