Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Island

Battle Screech

Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Elite Guardmage

Flying
When Elite Guardmage enters, you gain 3 life and draw a card.

Pride of the Clouds

Flying
Pride of the Clouds gets +1/+1 for each other creature on the battlefield with flying.
Forecast — {2}{W}{U}, Reveal Pride of the Clouds from your hand: Create a 1/1 white and blue Bird creature token with flying. (Activate only during your upkeep and only once each turn.)

Answered Prayers

Whenever a creature you control enters, you gain 1 life. If Answered Prayers isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Angel of Grace

Flash
Flying
When Angel of Grace enters, until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead.
{4}{W}{W}, Exile Angel of Grace from your graveyard: Your life total becomes 10.

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Always Watching

Nontoken creatures you control get +1/+1 and have vigilance.

Segovian Angel

Nahiri, Storm of Stone

During your turn, creatures you control have first strike and equip abilities you activate cost {1} less to activate.
−X: Nahiri, Storm of Stone deals X damage to target tapped creature.

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

Ascended Lawmage

Flying
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Plains

Defiant Strike

Target creature gets +1/+0 until end of turn.
Draw a card.

Worship

If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead.

Angel of Invention

Flying, vigilance, lifelink
Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)
Other creatures you control get +1/+1.

Faerie Seer

Flying
When Faerie Seer enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)