What about royal road when you literally burn a card? Do you have a problem when that card is returned to your deck? Or why do you never run out of cards? Do you merely show a card to someone instead of giving it to them? Do the stars grant you more cards in the heat of battle? Are cards really physical manifestations of the stars power? In that case, maybe pulling a certain cards freezes the stars aetheric tendency and prevents you from conjuring the duplicate by redrawing? Just a thought