The Cave of Skulls

Each creature card in your graveyard has scavenge. The scavenge cost is equal to its mana cost. (Exile a creature card from your graveyard and pay its mana cost: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Whenever chaos ensues, create two 1/1 white Warrior creature tokens.

Have

Shadowblood Ridge

Dark Ritual

Getting

Foreboding Ruins

As Foreboding Ruins enters the battlefield, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters the battlefield tapped.
{T}: Add {B} or {R}.

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Don't Have

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Flamerush Rider

Whenever Flamerush Rider attacks, create a token that's a copy of another target attacking creature and that's tapped and attacking. Exile the token at end of combat.
Dash {2}{R}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

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.")

Urabrask's Forge

At the beginning of combat on your turn, put an oil counter on Urabrask's Forge, then create an X/1 red Phyrexian Horror creature token with trample and haste, where X is the number of oil counters on Urabrask's Forge. Sacrifice that token at the beginning of the next end step.

Laser Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Tap target artifact.
{2}, {T}: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
{3}, {T}: Goad target creature. (Until your next turn, it attacks each combat if able and attacks a player other than you if able.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Prime Minister's Cabinet Room

At the beginning of combat on your turn, up to one target creature you control becomes a copy of target creature an opponent controls.
Will of the council — Whenever chaos ensues, starting with you, each player votes for a creature you don't control. Exile each creature with the most votes or tied for most votes.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Besieged Viking Village

All creatures have "Boast — {1}: Put a +1/+1 counter on this creature." (Activate only if that creature attacked this turn and only once each turn.)
Whenever chaos ensues, put an indestructible counter on target creature you control that attacked this turn.

The Dining Car

When you planeswalk to The Dining Car, each player creates a Food token.
Sixty-Six Seconds — At the beginning of your upkeep, sacrifice a creature with the least toughness among creatures you control. Then investigate.
Whenever chaos ensues, activated abilities of artifact tokens you control cost {2} less to activate this turn.

Impact Tremors

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

Kerblam! Warehouse

Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Whenever chaos ensues, until your next turn, noncreature artifacts you control gain "{T}, Sacrifice this artifact: Flip a coin. If you win the flip, this artifact deals 3 damage to any target."

Raucous Theater

({T}: Add {B} or {R}.)
Raucous Theater enters the battlefield tapped.
When Raucous Theater enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Sign in Blood

Target player draws two cards and loses 2 life.

Talisman of Indulgence

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

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Jaxis, the Troublemaker

{R}, {T}, Discard a card: Create a token that's a copy of another target creature you control. It gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step. Activate only as a sorcery.
Blitz {1}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Delina, Wild Mage

Whenever Delina, Wild Mage attacks, choose target creature you control, then roll a d20.
1—14 | Create a tapped and attacking token that's a copy of that creature, except it's not legendary and it has "At end of combat, exile this creature."
15—20 | Create one of those tokens. You may roll again.

Blood Crypt

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

The Sound of Drums

Enchant creature
Enchanted creature is goaded.
If enchanted creature would deal combat damage to a permanent or player, it deals double that damage instead.
{2}{R}: Return The Sound of Drums from your graveyard to your hand.

New New York

At the beginning of combat on your turn, until end of turn, noncreature artifacts you control become 3/3 Vehicles in addition to their other types and gain flying, haste, and crew 1.
Whenever chaos ensues, create a Treasure token and a 2/2 white Alien creature token.

The Matrix of Time

When you planeswalk to The Matrix of Time, each player exiles the top card of their library.
During your turn, you may play lands and cast spells from among cards exiled with The Matrix of Time.
Whenever you play a land or cast a spell from among cards exiled with The Matrix of Time, that card's owner loses 3 life and exiles the top card of their library.
Whenever chaos ensues, create two Treasure tokens.

Spectrox Mines

When you planeswalk to Spectrox Mines and at the beginning of your upkeep, you lose 3 life and create a Treasure token.
Whenever chaos ensues, create a Food token and a 2/2 black Human Rogue creature token.

The Master, Multiplied

Myriad
The "legend rule" doesn't apply to creature tokens you control.
Triggered abilities you control can't cause you to sacrifice or exile creature tokens you control.

Mountain

Mordor on the March

Exile a creature card from your graveyard. Create a token that's a copy of it. It gains haste until end of turn. Exile it at the beginning of the next end step.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Bad Wolf Bay

At the beginning of combat on your turn, exile up to one target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.
When chaos ensues, cards can't enter the battlefield from exile this turn. Then planeswalk.

Thought Vessel

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

Ominous Cemetery

{T}: Add {C}.
{5}, {T}, Exile Ominous Cemetery: Target creature's owner shuffles it into their library.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Fixed Point in Time

When you encounter Fixed Point in Time, until your next turn, if a player would planeswalk as a result of rolling the planar die, chaos ensues instead. (Then planeswalk away from this phenomenon.)

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Evolving Wilds

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

Feed the Swarm

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

Human-Time Lord Meta-Crisis

When you encounter Human-Time Lord Meta-Crisis, each player chooses one or two creatures they control. Each player creates a token that's a copy of the first creature they chose, except it isn't legendary. Then each player who chose a second creature puts a number of +1/+1 counters on the token they created equal to the power of the second creature they chose. (Then planeswalk away from this phenomenon.)

Aplan Mortarium

Byzantium Radiation — At the beginning of your upkeep, put an exposure counter on Aplan Mortarium. Then you lose life equal to the number of exposure counters on it.
Whenever chaos ensues, create two 2/2 black Alien Angel artifact creature tokens with first strike, vigilance, and "Whenever an opponent casts a creature spell, this permanent isn't a creature until end of turn."

Banshee of the Dread Choir

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Banshee of the Dread Choir deals combat damage to a player, that player discards a card.

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Seething Song

Coal Hill School

Whenever a player casts a historic spell, that player draws a card. (Artifacts, legendaries, and Sagas are historic.)
Whenever chaos ensues, return target historic card from your graveyard to your hand.

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Ood Sphere

Song of the Ood — Noncreature spells have convoke. (A player's creatures can help cast those spells. Each creature they tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
Red-Eye — Whenever chaos ensues, for each opponent, goad up to one target creature that opponent controls. Until your next turn, those creatures can't become tapped unless they're being declared as attackers.

The Doctor's Tomb

If a creature would die, instead exile it and that creature's controller loses 2 life.
Whenever chaos ensues, redistribute any number of players' life totals. (Each of those players gets one life total back.)

Terramorphic Expanse

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

Lightning Greaves

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

The Moonbase

Low Gravity — All creatures have "{2}: This creature gains flying until end of turn. Activate only as a sorcery."
Whenever chaos ensues, for each opponent, choose up to one target creature card in that player's graveyard. Put those cards onto the battlefield face down under your control. They're 2/2 Cyberman artifact creatures.

Singing Towers of Darillium

Each nonland card in your hand without foretell has foretell. Its foretell cost is equal to its mana cost reduced by {2}. (During your turn, you may pay {2} and exile it from your hand face down. Cast it on a later turn for its foretell cost.)
Whenever chaos ensues, you may cast a foretold card you own from exile without paying its mana cost this turn.

Temple of Malice

Temple of Malice enters the battlefield tapped.
When Temple of Malice enters the battlefield, scry 1.
{T}: Add {B} or {R}.

Temple of Atropos

At the beginning of your postcombat main phase, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)
When chaos ensues, reverse the game's turn order. Then planeswalk. (For example, if play had proceeded clockwise around the table, it now goes counterclockwise.)

Warstorm Surge

Whenever a creature enters the battlefield under your control, it deals damage equal to its power to any target.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Elturel Survivors

Trample, myriad
As long as Elturel Survivors is attacking, it gets +X/+0, where X is the number of lands defending player controls.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Dalek Intensive Care

When you planeswalk to Dalek Intensive Care and at the beginning of your upkeep, exile a non-Dalek creature you control. If you do, create a 3/3 black Dalek artifact creature token with menace. It gains haste until end of turn.
Whenever chaos ensues, target Dalek you control deals damage equal to its power to target creature you don't control.

Rogue's Passage

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

Rakdos Signet

Command Tower

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

North Pole Research Base

At the beginning of your upkeep, target opponent draws a card and creates a Treasure token.
Whenever chaos ensues, create a 2/2 white Alien creature token. When you do, tap target nontoken creature an opponent controls. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Gardens of Tranquil Repose

Suspended Animation — Whenever a creature dies, exile it. Its controller scries 1.
Whenever chaos ensues, create X 3/3 black Dalek artifact creature tokens with menace, where X is one plus the number of cards exiled with Gardens of Tranquil Repose.

Mondassian Colony Ship

Whenever a creature attacks, it gets +1/+1 until end of turn for each other creature its controller controls that shares a creature type with it.
Whenever chaos ensues, turn target creature face down. It becomes a 2/2 Cyberman artifact creature.

Mirror March

Whenever a nontoken creature enters the battlefield under your control, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Antarctic Research Base

When you planeswalk to Antarctic Research Base and at the beginning of your upkeep, investigate.
Whenever chaos ensues, put X +1/+1 counters on target creature you control, where X is the number of artifacts you control. It becomes a Plant in addition to its other types.

TARDIS Bay

The first spell you cast during each of your turns with mana value 2 or greater has cascade. (When you cast that spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
When chaos ensues, gain control of target artifact. Then planeswalk.

Hate Mirage

Choose up to two target creatures you don't control. For each of those creatures, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Rionya, Fire Dancer

At the beginning of combat on your turn, create X tokens that are copies of another target creature you control, where X is one plus the number of instant and sorcery spells you've cast this turn. They gain haste. Exile them at the beginning of the next end step.

Bojuka Bog

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

Orthion, Hero of Lavabrink

{1}{R}, {T}: Create a token that's a copy of another target creature you control. It gains haste. Sacrifice it at the beginning of the next end step. Activate only as a sorcery.
{6}{R}{R}{R}, {T}: Create five tokens that are copies of another target creature you control. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.

Determined Iteration

At the beginning of combat on your turn, populate. The token created this way gains haste. Sacrifice it at the beginning of the next end step. (To populate, create a token that's a copy of a creature token you control.)

The Doctor's Childhood Barn

Creatures enter the battlefield tapped.
Whenever chaos ensues, for each opponent, choose up to one target nonland permanent that opponent controls. Untap those permanents. They phase out. They can't phase in for as long as The Doctor's Childhood Barn remains face up. When a player planeswalks, those permanents phase in.

City of the Daleks

Whenever you attack, target opponent loses X life, where X is the number of artifacts you control.
Whenever chaos ensues, for each opponent, you create a 3/3 black Dalek artifact creature token with menace that attacks that opponent this turn if able. Those tokens gain haste. Sacrifice them at the beginning of the next end step.

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Warchief Giant

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

The Cheetah Planet

When you planeswalk to The Cheetah Planet and at the beginning of your upkeep, put two +1/+1 counters on target non-Cat creature you control. It becomes a Cat in addition to its other types.
Whenever chaos ensues, all Cats gain provoke until end of turn. (Whenever a Cat attacks, its controller may have target creature defending player controls untap and block it if able.)

The Drum, Mining Facility

Whenever you roll the planar die, creatures you control get +1/+1 and gain haste until end of turn.
Whenever chaos ensues, end the turn. (Exile all spells and abilities from the stack. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Sol Ring

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Hotel of Fears

At the beginning of your upkeep, exile the top card of your library. You lose life equal to its mana value. You may play that card this turn.
Praise Him — Whenever chaos ensues, choose a color. Put X +1/+1 counters on target creature you control, where X is your devotion to that color. Then sacrifice another creature. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Two Streams Facility

Whenever you planeswalk to Two Streams Facility and at the beginning of the first upkeep of the game, each player chooses green anchor or red waterfall.
Each player who last chose green anchor may play an additional land during each of their turns.
Creatures controlled by players who last chose red waterfall get +2/+0 and have haste.
Whenever chaos ensues, each player who last chose green anchor chooses red waterfall, and vice versa.

Swamp

Haunted Ridge

Haunted Ridge enters the battlefield tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Amy's Home

When you planeswalk to Amy's Home and at the beginning of your upkeep, you may exile a nonland card from your hand with a number of time counters on it equal to its mana value. If it doesn't have suspend, it gains suspend.
Whenever chaos ensues, time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)

Unleash the Flux

When you encounter Unleash the Flux, each player sacrifices a nonland permanent, then you flip a coin. If you lose the flip, repeat this process. (Then planeswalk away from this phenomenon.)