Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Ms. Bumbleflower

Vigilance
Whenever you cast a spell, target opponent draws a card. Put a +1/+1 counter on target creature. It gains flying until end of turn. If this is the second time this ability has resolved this turn, you draw two cards.

Oran-Rief Recluse

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Reach (This creature can block creatures with flying.)
When Oran-Rief Recluse enters, if it was kicked, destroy target creature with flying.

Web Shot

Destroy target creature with flying. (Then exile this card. You may cast the creature later from exile.)

Ettercap

Ettercap // Web Shot

Guardian of Solitude

Whenever you cast a Spirit or Arcane spell, target creature gains flying until end of turn.

Arnjlot's Ascent

Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
{1}: Target creature gains flying until end of turn.

Frostweb Spider

Reach (This creature can block creatures with flying.)
Whenever Frostweb Spider blocks a creature with flying, put a +1/+1 counter on Frostweb Spider at end of combat.

Stingerfling Spider

Reach
When Stingerfling Spider enters, you may destroy target creature with flying.

Silklash Spider

Reach
{X}{G}{G}: Silklash Spider deals X damage to each creature with flying.

Eutropia the Twice-Favored

Constellation — Whenever an enchantment you control enters, put a +1/+1 counter on target creature. That creature gains flying until end of turn.