Card Shark

Whenever Card Shark enters the battlefield or attacks, start a gamble (each player reveals a card
from their hand, the player who revealed the card
with the highest converted mana cost wins the
gamble; if there is a tie for highest converted
mana cost, repeat this process until there is a
winner; any player that wins a gamble may cast
any gambled spells without paying their mana
costs; any gambled lands are put onto the battlefield under the winner's control).