Mesa Unicorn

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

Storm Herd

Create X 1/1 white Pegasus creature tokens with flying, where X is your life total.

Sunmane Pegasus

Flying
{1}{W}: This creature gains vigilance and lifelink until end of turn. (Attacking doesn't cause it to tap. Damage dealt by it also causes you to gain that much life.)

Avacyn, Angel of Hope

Flying, vigilance, indestructible
Other permanents you control have indestructible.

Pegasus Courser

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

Phyrexian Rebirth

Destroy all creatures, then create an X/X colorless Phyrexian Horror artifact creature token, where X is the number of creatures destroyed this way.

Brightmare

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

Pegasus Charger

Flying (This creature can't be blocked except by creatures with flying or reach.)
First strike (This creature deals combat damage before creatures without first strike.)

Splendor Mare

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

Sol Ring

Sungrace Pegasus

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

Valorous Steed

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

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.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Regal Unicorn

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Steadfast Unicorn

{3}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn. Activate only during your turn. (Attacking doesn't cause them to tap.)

Mistral Charger

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Summon: Ixion

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Aerospark — Exile target creature an opponent controls until this Saga leaves the battlefield.
II, III — Put a +1/+1 counter on each of up to two target creatures you control. You gain 2 life.
First strike

Arborea Pegasus

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

Trusted Pegasus

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

Phyrexian Pegasus

Flying
Whenever this creature attacks, another target attacking creature without flying gains flying until end of turn.

Stormfront Pegasus

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Loyal Pegasus

Flying
This creature can't attack or block alone.

Armored Warhorse

Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Daybreak Charger

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

Plains

Shield Mare

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

Inspiring Unicorn

Whenever this creature attacks, creatures you control get +1/+1 until end of turn.

Pearled Unicorn

Opaline Unicorn

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.)

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Regal Bunnicorn

Regal Bunnicorn's power and toughness are each equal to the number of nonland permanents you control.

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.

Bill the Pony

When Bill the Pony enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.

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.

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.

Diamond Mare

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

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.

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.

Boreas Charger

Flying
When this creature 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.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Celestial Unicorn

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

Swords to Plowshares

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

Revered Unicorn

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When this creature leaves the battlefield, you gain life equal to the number of age counters on it.

Concordia Pegasus

Hour of Revelation

This spell costs {3} less to cast if there are ten or more nonland permanents on the battlefield.
Destroy all nonland permanents.

Sunfall

Exile all creatures. Incubate X, where X is the number of creatures exiled this way. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)

Armored Pegasus

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Ronom Unicorn

Sacrifice this creature: Destroy target enchantment.

Rider in Need

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the creature later from exile.)

Lonesome Unicorn

Lonesome Unicorn // Rider in Need

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.

Farewell

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

Benevolent Unicorn

If a spell would deal damage to a permanent or player, it deals that much damage minus 1 to that permanent or player instead.

Plated Pegasus

Flash (You may cast this spell any time you could cast an instant.)
Flying
If a spell would deal damage to a permanent or player, prevent 1 damage that spell would deal to that permanent or player.

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.