Glacial Chasm

Cumulative upkeep—Pay 2 life. (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 Glacial Chasm enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Swarmyard Massacre

Create two 1/1 green Squirrel creature tokens. Then each creature that isn't an Insect, Rat, Spider, or Squirrel gets -1/-1 until end of turn for each creature you control that's an Insect, Rat, Spider, or Squirrel.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Propaganda

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Swamp

Force of Despair

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.
Destroy all creatures that entered this turn.

Talisman of Dominance

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

Beyeen Coast

Beyeen Coast enters tapped.
{T}: Add {U}.

Beyeen Veil

Creatures your opponents control get -2/-0 until end of turn.

Beyeen Veil // Beyeen Coast

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Sky Diamond

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Deadly Rollick

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

Mind Stone

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

Dark Ritual

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Fellwar Stone

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

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Dispel

Sinister Concierge

When Sinister Concierge dies, you may exile it and put three time counters on it. If you do, exile up to one target creature and put three time counters on it. Each card exiled this way that doesn't have suspend gains suspend. (For each card with suspend, its owner removes a time counter from it at the beginning of their upkeep. When the last is removed, they may cast it without paying its mana cost. Those creature spells have haste.)

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Umbris, Fear Manifest

Umbris, Fear Manifest gets +1/+1 for each card your opponents own in exile.
Whenever Umbris or another Nightmare or Horror you control enters, target opponent exiles cards from the top of their library until they exile a land card.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

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}.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Arcane Signet

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

Dimir Signet

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Ponder

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

Mirror of Life Trapping

Whenever a creature enters, if it was cast, exile it, then return all other permanent cards exiled with Mirror of Life Trapping to the battlefield under their owners' control.

Drowned Catacomb

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

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Black Market Connections

At the beginning of your first main phase, choose one or more —
• Sell Contraband — Create a Treasure token. You lose 1 life.
• Buy Information — Draw a card. You lose 2 life.
• Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Darkness

Prevent all combat damage that would be dealt this turn.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Sol Ring

Command Tower

Volatile Stormdrake

Flying, hexproof from activated and triggered abilities
When Volatile Stormdrake enters, exchange control of Volatile Stormdrake and target creature an opponent controls. If you do, you get {E}{E}{E}{E}, then sacrifice that creature unless you pay an amount of {E} equal to its mana value.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Vren, the Relentless

Ward {2}
If a creature an opponent controls would die, exile it instead.
At the beginning of each end step, create X 1/1 black Rat creature tokens with "This creature gets +1/+1 for each other Rat you control," where X is the number of creatures that were exiled under your opponents' control this turn.

Mistcaller

Sacrifice Mistcaller: Until end of turn, if a nontoken creature would enter and it wasn't cast, exile it instead.

Temple of Deceit

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 {B}.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Soporific Springs

As Soporific Springs enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Dress Down

Flash
When Dress Down enters, draw a card.
Creatures lose all abilities.
At the beginning of the end step, sacrifice Dress Down.

Swan Song

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

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Soul-Guide Lantern

When this artifact enters, exile target card from a graveyard.
{T}, Sacrifice this artifact: Exile each opponent's graveyard.
{1}, {T}, Sacrifice this artifact: Draw a card.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Sunken Hollow

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

Misleading Signpost

Flash
When Misleading Signpost enters during the declare attackers step, you may reselect which player or permanent target attacking creature is attacking. (It can't attack its controller or their permanents.)
{T}: Add {U}.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Suspend

Exile target creature and put two time counters on it. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Island

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Mandate of Abaddon

Choose target creature you control. Destroy all creatures with power less than that creature's power.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Portcullis

Whenever a creature enters, if there are two or more other creatures on the battlefield, exile that creature. Return that card to the battlefield under its owner's control when Portcullis leaves the battlefield.

Choked Estuary

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Chromatic Lantern

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

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Thought Vessel

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

Ashiok, Nightmare Muse

+1: Create a 2/3 blue and black Nightmare creature token with "Whenever this creature attacks or blocks, each opponent exiles the top two cards of their library."
−3: Return target nonland permanent to its owner's hand, then that player exiles a card from their hand.
−7: You may cast up to three spells from among face-up cards your opponents own from exile without paying their mana costs.