Spectator Seating

Spectator Seating enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Izzet Signet

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Island

Coveted Jewel

When Coveted Jewel enters the battlefield, draw three cards.
{T}: Add three mana of any one color.
Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of Coveted Jewel. Untap it.

Vesuva

You may have Vesuva enter the battlefield tapped as a copy of any land on the battlefield.

Reflect Damage

The next time a source of your choice would deal damage this turn, that damage is dealt to that source's controller instead.

Sol Ring

Ruhan of the Fomori

At the beginning of combat on your turn, choose an opponent at random. Ruhan of the Fomori attacks that player this combat if able.

Reflecting Pool

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

Comeuppance

Prevent all damage that would be dealt to you and planeswalkers you control this turn by sources you don't control. If damage from a creature source is prevented this way, Comeuppance deals that much damage to that creature. If damage from a noncreature source is prevented this way, Comeuppance deals that much damage to the source's controller.

Solar Blaze

Each creature deals damage to itself equal to its power.

Angel of Indemnity

Flying, lifelink
When Angel of Indemnity enters the battlefield, return target permanent card with mana value 4 or less from your graveyard to the battlefield.
Encore {6}{W}{W} ({6}{W}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Confounding Conundrum

When Confounding Conundrum enters the battlefield, draw a card.
Whenever a land enters the battlefield under an opponent's control, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand.

Hallowed Fountain

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

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Lightmine Field

Whenever one or more creatures attack, Lightmine Field deals damage to each of those creatures equal to the number of attacking creatures.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Viashino Heretic

{1}{R}, {T}: Destroy target artifact. Viashino Heretic deals damage to that artifact's controller equal to the artifact's mana value.

Honorable Passage

The next time a source of your choice would deal damage to any target this turn, prevent that damage. If damage from a red source is prevented this way, Honorable Passage deals that much damage to the source's controller.

Plains

Thought Vessel

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

Mistveil Plains

({T}: Add {W}.)
Mistveil Plains enters the battlefield tapped.
{W}, {T}: Put target card from your graveyard on the bottom of your library. Activate only if you control two or more white permanents.

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Boros Reckoner

Whenever Boros Reckoner is dealt damage, it deals that much damage to any target.
{R/W}: Boros Reckoner gains first strike until end of turn.

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Aura Thief

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

Rod of Absorption

Whenever a player casts an instant or sorcery spell, exile it instead of putting it into a graveyard as it resolves.
{X}, {T}, Sacrifice Rod of Absorption: You may cast any number of spells from among cards exiled with Rod of Absorption with total mana value X or less without paying their mana costs.

Glacial Fortress

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

Mountain

Command Tower

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

Training Center

Training Center enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Illusory Ambusher

Flash (You may cast this spell any time you could cast an instant.)
Whenever Illusory Ambusher is dealt damage, draw that many cards.

Cooperate

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Refuse

Refuse deals damage to target spell's controller equal to that spell's mana value.

Refuse // Cooperate

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter the battlefield as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Boros Signet

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Hibernation

Return all green permanents to their owners' hands.

Raugrin Triome

({T}: Add {U}, {R}, or {W}.)
Raugrin Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter the battlefield tapped.

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.

Leadership Vacuum

Target player returns each commander they control from the battlefield to the command zone.
Draw a card.

Gilded Lotus

Phyrexian Vindicator

Flying
If damage would be dealt to Phyrexian Vindicator, prevent that damage. When damage is prevented this way, Phyrexian Vindicator deals that much damage to any other target.

Azorius Signet

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Mystic Monastery

Mystic Monastery enters the battlefield tapped.
{T}: Add {U}, {R}, or {W}.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Reiterate

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Clifftop Retreat

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

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.

Powerstone Minefield

Whenever a creature attacks or blocks, Powerstone Minefield deals 2 damage to it.

Thought Sponge

Flash
Thought Sponge enters the battlefield with a number of +1/+1 counters on it equal to the greatest number of cards an opponent has drawn this turn.
When Thought Sponge dies, draw cards equal to its power.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

The Wanderer

Prevent all noncombat damage that would be dealt to you and other permanents you control.
−2: Exile target creature with power 4 or greater.

Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Prisoner's Dilemma

Each opponent secretly chooses silence or snitch, then the choices are revealed. If each opponent chose silence, Prisoner's Dilemma deals 4 damage to each of them. If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them. Otherwise, Prisoner's Dilemma deals 12 damage to each opponent who chose silence.
Flashback {5}{R}{R}

Mirror Strike

All combat damage that would be dealt to you this turn by target unblocked creature is dealt to its controller instead.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

Day's Undoing

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Gather Specimens

If a creature would enter the battlefield under an opponent's control this turn, it enters the battlefield under your control instead.

Aether Flash

Whenever a creature enters the battlefield, Aether Flash deals 2 damage to it.

Mandate of Peace

Cast this spell only during combat.
Your opponents can't cast spells this turn.
End the combat phase. (Remove all attackers and blockers from combat. Exile all spells and abilities from the stack, including this spell.)

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Windborn Muse

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

Boros Fury-Shield

Prevent all combat damage that would be dealt by target attacking or blocking creature this turn. If {R} was spent to cast this spell, Boros Fury-Shield deals damage to that creature's controller equal to the creature's power.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Reliquary Tower

Take the Bait

Cast this spell only during an opponent's turn and only during combat.
Prevent all combat damage that would be dealt to you and planeswalkers you control this turn. Untap all attacking creatures and goad them. After this phase, there is an additional combat phase.

Gideon's Sacrifice

Choose a creature or planeswalker you control. All damage that would be dealt this turn to you and permanents you control is dealt to the chosen permanent instead (if it's still on the battlefield).

Arcane Signet

Copy Enchantment

You may have Copy Enchantment enter the battlefield as a copy of any enchantment on the battlefield.

Sunforger

Equipped creature gets +4/+0.
{R}{W}, Unattach Sunforger: Search your library for a red or white instant card with mana value 4 or less and cast that card without paying its mana cost. Then shuffle.
Equip {3}

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Desertion

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Sea of Clouds

Sea of Clouds enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Mischievous Quanar

{3}{U}{U}: Turn Mischievous Quanar face down.
Morph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Mischievous Quanar is turned face up, copy target instant or sorcery spell. You may choose new targets for that copy.