Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Remove?

Starfield Mystic

Enchantment spells you cast cost {1} less to cast.
Whenever an enchantment you control is put into a graveyard from the battlefield, put a +1/+1 counter on Starfield Mystic.

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Celestial Mantle

Enchant creature
Enchanted creature gets +3/+3.
Whenever enchanted creature deals combat damage to a player, double its controller's life total.

Traveler's Cloak

Enchant creature
As Traveler's Cloak enters, choose a land type.
When Traveler's Cloak enters, draw a card.
Enchanted creature has landwalk of the chosen type. (It can't be blocked as long as defending player controls a land of that type.)

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Snow-Covered Island

Disenchant

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Venser, the Sojourner

+2: Exile target permanent you own. Return it to the battlefield under your control at the beginning of the next end step.
−1: Creatures can't be blocked this turn.
−8: You get an emblem with "Whenever you cast a spell, exile target permanent."

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Sol Ring

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Faithful Mending

You gain 2 life, draw two cards, then discard two cards.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Danitha, Benalia's Hope

First strike, vigilance, lifelink
When Danitha, Benalia's Hope enters, you may put an Aura or Equipment card from your hand or graveyard onto the battlefield attached to Danitha.

Command Tower

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

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Getting

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Boomerang

Return target permanent to its owner's hand.

Pariah

Enchant creature
All damage that would be dealt to you is dealt to enchanted creature instead.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Myrel, Shield of Argive

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.
Whenever Myrel, Shield of Argive attacks, create X 1/1 colorless Soldier artifact creature tokens, where X is the number of Soldiers you control.

Cleansing Meditation

Destroy all enchantments.
Threshold — If seven or more cards are in your graveyard, instead destroy all enchantments, then return all cards in your graveyard destroyed this way to the battlefield.

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.

Zephid's Embrace

Enchant creature
Enchanted creature gets +2/+2 and has flying and shroud. (It can't be the target of spells or abilities.)

Faith Healer

Sacrifice an enchantment: You gain life equal to the sacrificed enchantment's mana value.

Hyena Umbra

Enchant creature
Enchanted creature gets +1/+1 and has first strike.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Umbra Mystic

Auras attached to permanents you control have umbra armor. (If an enchanted permanent you control would be destroyed, instead remove all damage from it and destroy an Aura attached to it.)

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Protective Bubble

Enchant creature
Enchanted creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Counterspell

Negate

Alexi's Cloak

Flash
Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)

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.

Eldrazi Conscription

Enchant creature
Enchanted creature gets +10/+10 and has trample and annihilator 2. (Whenever it attacks, defending player sacrifices two permanents of their choice.)

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Spectra Ward

Enchant creature
Enchanted creature gets +2/+2 and has protection from each color. This effect doesn't remove Auras. (It can't be blocked, targeted, or dealt damage by anything that's white, blue, black, red, or green.)

Timely Ward

You may cast Timely Ward as though it had flash if it targets a commander.
Enchant creature
Enchanted creature has indestructible.

Hallowed Fountain

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

Overburden

Whenever a player puts a nontoken creature onto the battlefield, that player returns a land they control to its owner's hand.

Glacial Fortress

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

Felidar Umbra

Enchant creature
Enchanted creature has lifelink.
{1}{W}: Attach Felidar Umbra to target creature you control.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Aura Thief

Flying
When Aura Thief dies, you gain control of all enchantments. (You don't get to move Auras.)

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Winds of Rath

Destroy all creatures that aren't enchanted. They can't be regenerated.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Skycloud Expanse

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Righteous Authority

Enchant creature
Enchanted creature gets +1/+1 for each card in its controller's hand.
At the beginning of the draw step of enchanted creature's controller, that player draws an additional card.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Magus of the Bazaar

{T}: Draw two cards, then discard three cards.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

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.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Sudden Disappearance

Exile all nonland permanents target player controls. Return the exiled cards to the battlefield under their owner's control at the beginning of the next end step.

Moorland Haunt

{T}: Add {C}.
{W}{U}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Enchanted Evening

All permanents are enchantments in addition to their other types.

Auramancer's Guise

Enchant creature
Enchanted creature gets +2/+2 for each Aura attached to it and has vigilance.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Sovereigns of Lost Alara

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, you may search your library for an Aura card that could enchant that creature, put it onto the battlefield attached to that creature, then shuffle.

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Kor Spiritdancer

Kor Spiritdancer gets +2/+2 for each Aura attached to it.
Whenever you cast an Aura spell, you may draw a card.

Ghostly Prison

Axis of Mortality

At the beginning of your upkeep, you may have two target players exchange life totals.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Arcane Signet

Island

Grand Abolisher

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.

Sage's Reverie

Enchant creature
When Sage's Reverie enters, draw a card for each Aura you control that's attached to a creature.
Enchanted creature gets +1/+1 for each Aura you control that's attached to a creature.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Heliod's Pilgrim

When Heliod's Pilgrim enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Snow-Covered Plains

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Proxy

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Indestructibility

Enchant permanent
Enchanted permanent has indestructible. (Effects that say "destroy" don't destroy that permanent. A creature with indestructible can't be destroyed by damage.)

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Bovine Intervention

Destroy target artifact or creature. Its controller creates a 2/2 white Ox creature token.

Plains

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

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.")

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Vanishing

Enchant creature
{U}{U}: Enchanted creature phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Battle Mastery

Enchant creature
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Stuffy Doll

Indestructible
As Stuffy Doll enters, choose a player.
Whenever Stuffy Doll is dealt damage, it deals that much damage to the chosen player.
{T}: Stuffy Doll deals 1 damage to itself.

Gift of Immortality

Enchant creature
When enchanted creature dies, return that card to the battlefield under its owner's control. Return Gift of Immortality to the battlefield attached to that creature at the beginning of the next end step.

Keeper of the Accord

At the beginning of each opponent's end step, if that player controls more creatures than you, create a 1/1 white Soldier creature token.
At the beginning of each opponent's end step, if that player controls more lands than you, you may search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Lonely Arroyo

Lonely Arroyo enters tapped.
When Lonely Arroyo enters, it deals 1 damage to target opponent.
{T}: Add {W} or {U}.

Dovescape

({W/U} can be paid with either {W} or {U}.)
Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.