Niv-Mizzet, Guildpact{W}{U}{B}{R}{G}

Legendary Creature — Dragon Avatar

Flying, hexproof from multicolored Whenever Niv-Mizzet deals combat damage to a player, it deals X damage to any target, target player draws X cards, and you gain X life, where X is the number of different color pairs among permanents you control that are exactly two colors.