Protection from multicolored

Protection from enemy-colored multicolored. (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything that's two enemy colors, such as blue and green.)

Multicolored creatures you control get +1/+1.

Flying

Whenever Guildpact Informant deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

+1: Look at the top two cards of your library. Put one of them into your graveyard.

−3: Return another target nonland permanent to its owner's hand.

−8: Each player shuffles their hand and graveyard into their library. You draw seven cards.

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.

Sphinx of the Guildpact is all colors.

Flying

Hexproof from monocolored (This creature can't be the target of monocolored spells or abilities your opponents control.)