Answer:
It's anything but amusing when this body part gets hit.
What is often returned but is never borrowed?
The man who invented it doesn't want it. The man who bought it doesn't need it. The man who needs it doesn't know it. What is it?
The person who makes it has no need for it. The person who purchases it does not use it. The person who does use it does not know he or she is. What is it?
I cut through evil like a double edged sword, and chaos flees at my approach. Balance I single-handedly upraise, through battles fought with heart and mind, instead of with my gaze.
I am free the first time and second time but the third time is going to cost you money.