nemesis
noun [ C ] literary uk/ˈnem.ə.sɪs/ us/ˈnem.ə.sɪs/ nemeses /ˈnem.ə.siːz/ /ˈnem.ə.siːz/
劲敌
Someone's nemesis is a person or thing that is very difficult for them to defeat.
报应，天谴；应得的惩罚；不可避免的失败
(a cause of) punishment or defeat that is deserved and cannot be avoided
The tax increases proved to be the president's political nemesis. 提高税收让总统自食恶果。