Nemeses

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

Eating too much junk food can be a nemeses to your waistline.

The hiker's nemeses, blisters on her feet, made it difficult for her to continue on the trail.

The detective and his nemeses engaged in a cat-and-mouse game that lasted for years.

The nemeses of the detective were always trying to outsmart him.

The hiker's nemeses were the difficult terrain and bad weather.