721.1. One card (Karn Liberated) restarts the game. A game that is restarted immediately ends. No
players in that game win, lose, or draw that game. All players in that game when it ended then start
a new game following the procedures set forth in rule 103, “Starting the Game,” with the following
721.1a The starting player in the new game is the player who controlled the spell or ability that
restarted the game.
The game ends and a new one begins. Thus no completed dungeon and no dungeon in progress.