Fateful Absence

Destroy target creature or planeswalker. Its controller investigates. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Getting

Thurid, Mare of Destiny

Flying, lifelink
Whenever you cast a Pegasus, Unicorn, or Horse creature spell, copy it. (The copy becomes a token.)
Other Pegasi, Unicorns, and Horses you control get +1/+1.

Have

Shepherd of the Clouds

Flying, vigilance
When Shepherd of the Clouds enters, return target permanent card with mana value 3 or less from your graveyard to your hand. Return that card to the battlefield instead if you control a Mount.

Ronom Unicorn

Sacrifice Ronom Unicorn: Destroy target enchantment.

The Grey Havens

When The Grey Havens enters, scry 1.
{T}: Add {C}.
{T}: Add one mana of any color among legendary creature cards in your graveyard.

Valorous Steed

Vigilance (Attacking doesn't cause this creature to tap.)
When Valorous Steed enters, create a 2/2 white Knight creature token with vigilance.

Sungrace Pegasus

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

Shield Mare

Shield Mare can't be blocked by red creatures.
When Shield Mare enters or becomes the target of a spell or ability an opponent controls, you gain 3 life.

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.

Archon of Sun's Grace

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Pegasus creatures you control have lifelink.
Constellation — Whenever an enchantment you control enters, create a 2/2 white Pegasus creature token with flying.

Angelic Chorus

Whenever a creature you control enters, you gain life equal to its toughness.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Daybreak Charger

When Daybreak Charger enters, target creature gets +2/+0 until end of turn.

Sky Tether

Enchant creature
Enchanted creature has defender and loses flying.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Pegasus Courser

Flying
Whenever Pegasus Courser attacks, another target attacking creature gains flying until end of turn.

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Loyal Unicorn

Vigilance
Lieutenant — At the beginning of combat on your turn, if you control your commander, prevent all combat damage that would be dealt to creatures you control this turn. Other creatures you control gain vigilance until end of turn.

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Leyline of Hope

If Leyline of Hope is in your opening hand, you may begin the game with it on the battlefield.
If you would gain life, you gain that much life plus 1 instead.
As long as you have at least 7 life more than your starting life total, creatures you control get +2/+2.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Horse

Ajani, Strength of the Pride

+1: You gain life equal to the number of creatures you control plus the number of planeswalkers you control.
−2: Create a 2/2 white Cat Soldier creature token named Ajani's Pridemate with "Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate."
0: If you have at least 15 life more than your starting life total, exile Ajani, Strength of the Pride and each artifact and creature your opponents control.

Angelic Gift

Enchant creature
When Angelic Gift enters, draw a card.
Enchanted creature has flying.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Inspiring Unicorn

Whenever Inspiring Unicorn attacks, creatures you control get +1/+1 until end of turn.

Nyxborn Unicorn

Bestow {3}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Enchanted creature gets +2/+2 and has mentor.

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Armored Warhorse

Boreas Charger

Flying
When Boreas Charger leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Pegasus

Opaline Unicorn

Arborea Pegasus

Flying
When Arborea Pegasus enters, target creature gets +1/+1 and gains flying until end of turn.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Mesa Unicorn

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

Parting Gust

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Exile target nontoken creature. If the gift wasn't promised, return that card to the battlefield under its owner's control with a +1/+1 counter on it at the beginning of the next end step.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.

Kabira Plateau

Kabira Plateau enters tapped.
{T}: Add {W}.

Kabira Takedown

Kabira Takedown deals damage equal to the number of creatures you control to target creature or planeswalker.

Kabira Takedown // Kabira Plateau

Wrath of God

Destroy all creatures. They can't be regenerated.

Disenchant

Trusted Pegasus

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Trusted Pegasus attacks, target attacking creature without flying gains flying until end of turn.

Majestic Auricorn

Mutate {3}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Vigilance
Whenever this creature mutates, you gain 4 life.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Destroy Evil

Choose one —
• Destroy target creature with toughness 4 or greater.
• Destroy target enchantment.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Doomskar

Destroy all creatures.
Foretell {1}{W}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Glaring Aegis

Enchant creature
When Glaring Aegis enters, tap target creature an opponent controls.
Enchanted creature gets +1/+3.

Armor of Faith

Enchant creature
Enchanted creature gets +1/+1.
{W}: Enchanted creature gets +0/+1 until end of turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Diamond Mare

As Diamond Mare enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Blessed Sanctuary

Prevent all noncombat damage that would be dealt to you and creatures you control.
Whenever a nontoken creature you control enters, create a 2/2 white Unicorn creature token.

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Trouble in Pairs

If an opponent would begin an extra turn, that player skips that turn instead.
Whenever an opponent attacks you with two or more creatures, draws their second card each turn, or casts their second spell each turn, you draw a card.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Sol Ring

Smuggler's Share

At the beginning of each end step, draw a card for each opponent who drew two or more cards this turn, then create a Treasure token for each opponent who had two or more lands enter the battlefield under their control this turn.

Karmic Justice

Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

True Conviction

Creatures you control have double strike and lifelink.

Splendor Mare

Lifelink
Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.)
When you cycle Splendor Mare, put a lifelink counter on target creature you control.

Revitalize

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Irregular Cohort

Changeling (This card is every creature type.)
When Irregular Cohort enters, create a 2/2 colorless Shapeshifter creature token with changeling.

Plains

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Spear of Heliod

Creatures you control get +1/+1.
{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Nahiri's Binding

Enchant creature or planeswalker
Enchanted permanent can't attack or block, and its activated abilities can't be activated.