Matt, Immune to Curiosity

When Matt enters the battlefield choose a card type, spells of the chosen type cost {1} more to cast.
Protection from the chosen type
Whenever you cast a spell of the chosen type, reveal cards from target opponent’s library until you reveal a card with equal mana cost. Then you may choose a card from among the revealed cards that shares a card type, cast that card without paying its mana cost. Then put the reveled cards on top of that players library in a random order.