The Challenger

When you cast this spell, Challenge an opponent.
(You and target opponent play a magic subgame at 1
life, with 5, 5 minute turns, using your libraries as
decks. During the subgame, players in the game
continue play. Permanents in the game controlled by
the players in the subgame phase out, and for the
duration of the subgame their life totals can't change
and they have protection from everything. The winner
of the subgame rejoins the game, the loser loses the
game, and if tied