Nemeses

Her lack of self-control when it came to spending was her financial nemeses.

Her mother was her nemeses when it came to fashion choices.

The musician's nemeses, stage fright and technical difficulties, affected her performance.

The computer virus was the nemeses of the company's entire network.

The nemeses of computer hackers are the cybersecurity experts who work to keep their networks safe.

Their nemeses were their fear of failure and lack of self-confidence.