Battle of Wills

You and target player bid life. You start the
bidding with a bid of 1. In turn order, you and
that player may each top the high bid. The
bidding ends if the high bid stands. The high
bidder loses life equal to the high bid and reveals
cards from the top of their library until they
reveal a spell with converted mana cost equal
to the high bid. Until end of turn, that player
may cast that spell without paying its converted
mana cost. When they do or the turn ends, that
player shuffles th