Ghoulcaller's War

When Ghoulcaller's War enters the battlefield,
destroy all creatures and each player puts the top thirteen cards of his or her library into his or her
graveyard.
At the beginning of each player's upkeep, that
player exiles two creature cards from his or her graveyard and then creates two tokens that are
copies of the cards exiled this way.
When a player has no creature cards left in their graveyard, then that player loses the game.