Blissful Harmony

Creatures and lands have "{t}: Add one mana of any color to your mana pool."
At the beginning of each player's precombat main phase, that player may add two mana of any one color to his or her mana pool. If he or she does, put a depletion counter on Blissful Harmony.
{x}{x}{b}{b}{b}, Remove X depletion counters from Blissful Harmony: Each opponent sacrifices X lands.