Imagination

You may reveal Imagination from your start hand. If you do, exile all cards in your hand other than this card and shuffle this card into your library. Then draw seven cards.
Imagination costs {1} less for each card you own in exile.
You have no maximum hand size.
At the beginning of your upkeep and end step, draw two cards.
Spells you cast cost {1} less to cast for each card you own in exile.