Flying {1}{U}, Sacrifice Fatewrench: Fateseal 2. (To fateseal 2, look at the top two cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)
No secret is safe from Mei's students, not even those that haven't been thought of yet.
When Featherfall Ascetic enters, create a 1/1 white and blue Bird creature token with flying. Whenever a nontoken Aura enters enchanting Featherfall Ascetic, for each other creature you control, you may create a token that's a copy of that Aura enchanting that creature.
Flying At the beginning of your upkeep, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Flying You may exert Fervent Igmel as it attacks. When you do, add {R}{R}{R}{R}. Until end of turn, you don't lose this mana as steps and phases end. (An exerted creature won't untap during your next untap step.)
Flying When Fickle Songstress enters, target opponent gains control of it. Whenever you lose life, if you don't own Fickle Songstress, its owner gains control of it.
Flying Vanishing (At the beginning of your upkeep, remove a time counter from this permanent. When the last is removed, sacrifice it.) Ficklewing Elemental enters with a time counter on it for each card in your hand.
At the beginning of each combat, you may have Firefish Conjurer deal 3 damage to target creature you control. If you do, Firefish Conjurer gets +2/+0 and gains flying until end of turn.
Target player mills four cards. Inscribed creature has flying. Inscribe {2}{U}({2}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)
Flying (This creature can't be blocked except by creatures with flying or reach.) At the beginning of your upkeep, put a +1/+1 counter on Fleshrender Demon and you lose 1 life.
Create X 4/4 white Angel creature tokens with flying. Flashback {X}{W}{W}{W}{W}{W}(You may cast this card from your graveyard for its flashback cost. Then exile it.)