nemesis
Pronunciation:
/ˈnɛməsɪs/noun
Definitions
An archenemy
Example: Batman is in constant conflict with his nemesis, The Joker.
(chiefly non-North American usage) A person or character who specifically brings about the downfall of another person or character.
The principle of retributive justice.
(usually in the singular) A punishment or defeat that is deserved and cannot be avoided.