Lifecreed Duo

Flying
Whenever another creature you control enters, you gain 1 life.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Ruin-Lurker Bat

Flying, lifelink
At the beginning of your end step, if you descended this turn, scry 1. (You descended if a permanent card was put into your graveyard from anywhere.)

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Abandoned Campground

This land enters tapped unless a player has 13 or less life.
{T}: Add {W} or {U}.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Air Nomad Legacy

When this enchantment enters, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Creatures you control with flying get +1/+1.

No More Lies

Counter target spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Healer's Hawk

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

Sheltered by Ghosts

Enchant creature you control
When this Aura enters, exile target nonland permanent an opponent controls until this Aura leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Momo, Friendly Flier

Flying
The first non-Lemur creature spell with flying you cast during each of your turns costs {1} less to cast.
Whenever another creature you control with flying enters, Momo gets +1/+1 until end of turn.

Aang and La, Ocean's Fury

Reach, trample
Whenever Aang and La attack, put a +1/+1 counter on each tapped creature you control.

Aang, Swift Savior

Flash
Flying
When Aang enters, airbend up to one other target creature or spell. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Waterbend {8}: Transform Aang.