Blackjack

You and your opponent each exile the top card of
your libraries face down, and reveal the top card of
your library. Beginning with your opponent, take
turns revealing additional cards or declining.
When both players have declined consecutively,
reveal the exiled cards. The player with the greatest
total mana cost of revealed cards they own win the
game. A player with a combined converted mana cost
exceeding 21 automatically loses. If there is a tie, this spell has no effect. Shuffle the revealed c