Very traditional line spoken as the hero has the villain in their power. It could be said by the hero, the former Distressed Damsel, or even the villain themselves if they're aware of the rules of the trope. The goal is to evoke a Not So Different moment. In most cases in which the situation plays out exactly like this that doesn't involve a Karmic Death also involves not bringing the villain to any other form of justice whatsoever. That is, unless the hero personally administers Cruel Mercy, which may in fact be worse than having simply killed them. Or cooler.