Nemeses

The detective knew that the elusive criminal was his nemeses, always managing to evade capture.

The journalist's nemeses, the lack of reliable sources and conflicting information, made it hard for her to report the truth.

Her addiction to alcohol was one of her nemeses.

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.

The nemeses of the criminal underworld are the police officers who tirelessly work to bring them to justice.