Text (MR/10/M10): 4/4, Flying. ; You can't lose the game and your opponents can't win the game.
Effects that say the game is a draw still work. [Mirrodin FAQ 2003/10/01]
In multiplayer games, your teammates can still lose, but opponents can't win. [Mirrodin FAQ 2003/10/01]
You can concede the game with this card in play. [Mirrodin FAQ 2003/10/01]
In tournament play, if the game ends with this card in play, the "highest total life" rule can declare a player the winner. [Mirrodin FAQ 2003/10/01]
If your life total is 20 or more and you control both this card and Transcendence, then an infinite loop is formed. If neither player wants to end the loop by removing one of these two cards from play, the game ends in a draw. [WotC Rules Team 2003/10/01]
If an effect like Door to Nothingness tries to cause you to lose the game, you do not lose. This card wins out due to Rule 101.2. [D'Angelo 2006/02/07] Same for Phage the Untouchable. [D'Angelo 2006/03/11]
