Deathrite, Lost Graveyard

+1: Exile target land card from a graveyard. Add one mana of any color.
-1: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life or Exile target creature card from a graveyard. You gain 2 life
-6: Create two 1/1 black Assassin creature tokens with "Whenever this creature deals combat damage to a player, that player loses the game."