Polymath Mage

Spells you cast cost {1} less to cast for each of
their colors.
Whenever Polymath Mage attacks you may
reveal your hand. If you do, exile cards from the
top of your library until you exile a card that
does not share a card type or converted mana
cost with any of the cards revealed this way. Put
that card into your hand and shuffle the other
exiled cards into your library.