Chant of Vitu-Ghazi [March of the Machine Commander]

Set: March of the Machine Commander Type: Instant Rarity: Uncommon Cost: {6}{W}{W} Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)Prevent all damage that would be dealt by creatures this turn. You gain life equal to the damage prevented this way.