ball-breaker 
(also ball-buster)
noun informal
1A tough disciplinarian or taskmaster: to be one of the world’s best chefs, you have to be a ball-breaker
1.1A dominating or threatening woman who destroys a man’s self-confidence.But the new face of business is plainly better than the old school: the women are assured without being ball-busters, the men are impatient with Felix's bigotry....
- She was much taller than me, and all the guys described her as an Amazon, which in their circles meant that she was a ball-buster.
- I know you're married to a ball-buster who earns seven figures and that you lost your job three years ago, right around the time you started losing your hair.
1.2A demanding and punishing task or situation: the early stretch of the race is the ball-breaker
Derivatives
ball-breaking
- The e-mail she sent you seems rather intrusive, if not ball-busting, but forewarned is forearmed.
- It seems that these people are going around trying to create publicity for themselves in the most underhanded, backstabbing, ball-busting ways imaginable.
- It's really not all that simple anymore, given the huge strides in gear and ball-busting confidence, particularly among American climbers.