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}

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Mountain

Waterlogged Grove

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice this land: Draw a card.

Force of Vigor

If it's not your turn, you may exile a green card from your hand rather than pay this spell's mana cost.
Destroy up to two target artifacts and/or enchantments.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Pull from Tomorrow

Reap

Return up to X target cards from your graveyard to your hand, where X is the number of black permanents target opponent controls as you cast this spell.

Fortune Teller's Talent

(Gain the next level as a sorcery to add its ability.)
You may look at the top card of your library any time.
{3}{U}: Level 2
As long as you've cast a spell this turn, you may play cards from the top of your library.
{2}{U}: Level 3
Spells you cast from anywhere other than your hand cost {2} less to cast.

Rootbound Crag

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Overgrown Tomb

({T}: Add {B} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Swan Song

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

Sol Ring

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Steam Vents

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

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Birds of Paradise

Exotic Orchard

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

Nyxbloom Ancient

Trample
If you tap a permanent for mana, it produces three times as much of that mana instead.

Volcanic Vision

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's mana value to each creature your opponents control. Exile Volcanic Vision.

Dualcaster Mage

Flash
When this creature enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Forest

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Font of Magic

Instant and sorcery spells you cast cost {1} less to cast for each time you've cast a commander from the command zone this game.

Time Stretch

Target player takes two extra turns after this one.

Temporal Trespass

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Take an extra turn after this one. Exile Temporal Trespass.

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Keen Sense

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

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Fierce Guardianship

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

Swamp

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Deadly Rollick

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

Temporal Manipulation

Stroke of Genius

Vedalken Orrery

You may cast spells as though they had flash.

Nissa's Expedition

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Sakura-Tribe Scout

{T}: You may put a land card from your hand onto the battlefield.

Lightning Greaves

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

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Blasphemous Act

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

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Hagra Broodpit

Hagra Mauling

This spell costs {1} less to cast if an opponent controls no basic lands.
Destroy target creature.

Hagra Mauling // Hagra Broodpit

Thrasios, Triton Hero

{4}: Scry 1, then reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. Otherwise, draw a card.
Partner (You can have two commanders if both have partner.)

Windgrace's Judgment

For any number of opponents, destroy target nonland permanent that player controls.

Temple of Malady

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {G}.

Exploration

You may play an additional land on each of your turns.

Misty Rainforest

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

Reliquary Tower

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

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Command Tower

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

Mystic Peak

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Augur of Autumn

You may look at the top card of your library any time.
You may play lands from the top of your library.
Coven — As long as you control three or more creatures with different powers, you may cast creature spells from the top of your library.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Evolving Wilds

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

Terramorphic Expanse

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Mystic Remora

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.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Siren Stormtamer

Flying
{U}, Sacrifice this creature: Counter target spell or ability that targets you or a creature you control.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Calamity of Cinders

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Calamity of Cinders deals 6 damage to each untapped creature.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Watery Grave

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

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Jace, Telepath Unbound

+1: Up to one target creature gets -2/-0 until your next turn.
−3: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead.
−9: You get an emblem with "Whenever you cast a spell, target opponent mills five cards."

Jace, Vryn's Prodigy

{T}: Draw a card, then discard a card. If there are five or more cards in your graveyard, exile Jace, then return him to the battlefield transformed under his owner's control.

Jace, Vryn's Prodigy // Jace, Telepath Unbound

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put this artifact on top of its owner's library.

Curtains' Call

Undaunted (This spell costs {1} less to cast for each opponent.)
Destroy two target creatures.

Breeding Pool

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

Time Warp

Target player takes an extra turn after this one.

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Island

Curiosity

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.