Flying (This creature can't be blocked except by creatures with flying or reach.),
hexproof from multicolored
(This permanent can't be the target of spells or abilities your opponents control.)
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.