Niv-Mizzet, Guildpact [Murders at Karlov Manor Prerelease Promos]

Flying, hexproof from multicolored

Whenever Niv-Mizzet, Guildpact 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.