This is a question I have pondered for some time. Say I use Gardevoir's Psyshadow power to look through my deck and find an energy, but there are none to be found. Do I have to show my deck to my opponent to prove that there are indeed no psychic energies? This of course is about all cards like that who do not have the option to choose a card in them. How would you go about proving that there aren't any in your deck, or does your opponent just have to take your word for it?