Acolyte's Reward

Prevent the next X damage that would be dealt to target creature this turn, where X is your devotion to white. If damage is prevented this way, Acolyte's Reward deals that much damage to any target. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Adanto Vanguard

As long as Adanto Vanguard is attacking, it gets +2/+0.
Pay 4 life: Adanto Vanguard gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Ajani's Sunstriker

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

Aegis of the Gods

You have hexproof. (You can't be the target of spells or abilities your opponents control.)

Ageless Guardian

Amaranthine Wall

Defender
{2}: Amaranthine Wall gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Knowledge Pool

Imprint — When Knowledge Pool enters, each player exiles the top three cards of their library.
Whenever a player casts a spell from their hand, that player exiles it. If the player does, they may cast a spell from among other cards exiled with Knowledge Pool without paying its mana cost.

Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Abeyance

Until end of turn, target player can't cast instant or sorcery spells, and that player can't activate abilities that aren't mana abilities.
Draw a card.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Ajani's Mantra

At the beginning of your upkeep, you may gain 1 life.

Alloy Myr

Baldin, Century Herdmaster

As long as it's your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin, Century Herdmaster attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Adarkar Valkyrie

Flying, vigilance
{T}: When target creature other than Adarkar Valkyrie dies this turn, return that card to the battlefield under your control.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Ageless Sentinels

Defender (This creature can't attack.)
Flying
When Ageless Sentinels blocks, it becomes a Bird Giant, and it loses defender. (It's no longer a Wall. This effect lasts indefinitely.)

Alaborn Cavalier

Whenever Alaborn Cavalier attacks, you may tap target creature.

Aegis of the Heavens

Target creature gets +1/+7 until end of turn.

Affa Protector

Aetherstorm Roc

Flying
Whenever Aetherstorm Roc or another creature you control enters, you get {E} (an energy counter).
Whenever Aetherstorm Roc attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Abiding Grace

At the beginning of your end step, choose one —
• You gain 1 life.
• Return target creature card with mana value 1 from your graveyard to the battlefield.