Priest of Possibility is a rare Creature — Kor Cleric card from Alchemy: Dominaria (YDMU), collector number 2.
When Priest of Possibility enters, look at the top seven cards of your library. If a card among them has flying, Priest of Possibility perpetually gains flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, and vigilance. Then shuffle.