Celestial Enforcer

{1}{W}, {T}: Tap target creature. Activate only if you control a creature with flying.

Concordia Pegasus

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Whenever Falconer Adept attacks, create a 1/1 white Bird creature token with flying that's tapped and attacking.

Flying
When Gale Swooper enters, target creature gains flying until end of turn.

Flying
Whenever Steel-Plume Marshal attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Destroy target tapped creature. You gain 1 life for each creature you control with flying.

Thriving Heath enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Up to two target creatures each get +2/+2 until end of turn.

Flying
When Aven Gagglemaster enters, you gain 2 life for each creature you control with flying.

Defender (This creature can't attack.)
Attacking creatures you control get +1/+0.