The Ten of Wands marks the moment when the energy of the wands becomes exhausted under too much pressure. When the Ten of Wands comes up, words like toil, burden and fatigue, too much, too long, come to mind. The Ace of Cups is usually a positive, beneficial influence, it's the point when things start looking up and it often predicts the beginning of a loving relationship.
The elements of the cards are Fire (Ten of Wands) and Water (Ace of Cups). The elements are in contrast and normally are fighting each other. The Ten of Wands has gathered all the fiery dynamic of its suite, but its energy is now exhausted, so it's usually easy for the Water card to make a difference, even if it's just an Ace.