Sulfurous Springs

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

Terramorphic Expanse

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

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Mirror-Style Master

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature attacks, for each attacking modified creature you control, create a tapped and attacking token that's a copy of that creature. Exile those tokens at end of combat. (Equipment, Auras you control, and counters are modifications.)

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Foreboding Ruins

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

Upriser Renegade

Upriser Renegade gets +2/+0 for each other modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Smoldering Marsh

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

Sunken Hollow

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

Gixian Infiltrator

Whenever you sacrifice another permanent, put a +1/+1 counter on Gixian Infiltrator.

Lethal Exploit

Target creature gets -2/-2 until end of turn. It gets an additional -1/-1 until end of turn for each modified creature you controlled as you cast this spell. (Equipment, Auras you control, and counters are modifications.)

Gloomfang Mauler

Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)
Backup 2 (When this creature enters, put two +1/+1 counters on target creature. If that's another creature, it gains the following ability until end of turn.)
Menace

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Archpriest of Shadows

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Deathtouch
Whenever this creature deals combat damage to a player or battle, return target creature card from your graveyard to 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}.

Thundering Raiju

Haste
Whenever Thundering Raiju attacks, put a +1/+1 counter on target creature you control. Then Thundering Raiju deals X damage to each opponent, where X is the number of modified creatures you control other than Thundering Raiju. (Equipment, Auras you control, and counters are modifications.)

Dimir Aqueduct

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

Erebos, Bleak-Hearted

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature.
Whenever another creature you control dies, you may pay 2 life. If you do, draw a card.
{1}{B}, Sacrifice another creature: Target creature gets -2/-1 until end of turn.

Drowned Catacomb

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

Marchesa's Smuggler

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
{1}{U}{R}: Target creature you control gains haste until end of turn and can't be blocked this turn.

Thran Vigil

Whenever one or more artifact and/or creature cards leave your graveyard during your turn, put a +1/+1 counter on target creature you control.

Lord Xander, the Collector

When Lord Xander, the Collector enters, target opponent discards half the cards in their hand, rounded down.
Whenever Lord Xander attacks, defending player mills half their library, rounded down.
When Lord Xander dies, target opponent sacrifices half the nonland permanents they control, rounded down.

Consuming Aetherborn

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Lifelink

Towashi Guide-Bot

When Towashi Guide-Bot enters, put a +1/+1 counter on target creature you control.
{4}, {T}: Draw a card. This ability costs {1} less to activate for each modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Coral Atoll

Coral Atoll enters tapped.
When Coral Atoll enters, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Etched Slith

Menace
Whenever Etched Slith deals combat damage to a player, put a +1/+1 counter on it. When you do, you may remove a counter from another target permanent or opponent.

Underground River

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

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Unforgiving One

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Unforgiving One attacks, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the number of modified creatures you control. (Equipment, Auras you control, and counters are modifications.)

Iron Apprentice

Iron Apprentice enters with a +1/+1 counter on it.
When Iron Apprentice dies, if it had counters on it, put those counters on target creature you control.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Annihilating Glare

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature.
Destroy target creature or planeswalker.

Izzet Signet

Sol Ring

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Island

Szat's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Each opponent sacrifices a creature they control with the greatest power.
• Exile all opponents' graveyards, then create X 0/1 black Thrull creature tokens, where X is the greatest power among creature cards exiled this way.

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

Dragonskull Summit

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

Scourge of the Throne

Flying
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Whenever Scourge of the Throne attacks for the first time each turn, if it's attacking the player with the most life or tied for most life, untap all attacking creatures. After this phase, there is an additional combat phase.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

River Kelpie

Whenever River Kelpie or another permanent enters from a graveyard, draw a card.
Whenever a player casts a spell from a graveyard, draw a card.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Blasphemous Act

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

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

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.")

Ashnod's Altar

Arcane Signet

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

Sulfur Falls

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

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Fellwar Stone

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

Ian the Reckless

Whenever Ian the Reckless attacks, if it's modified, you may have it deal damage equal to its power to you and any target. (Equipment, Auras you control, and counters are modifications.)

Hangar Scrounger

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature becomes tapped, you may discard a card. If you do, draw a card.

Treasonous Ogre

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Pay 3 life: Add {R}.

Bloodtracker

Flying
{B}, Pay 2 life: Put a +1/+1 counter on Bloodtracker.
When Bloodtracker leaves the battlefield, draw a card for each +1/+1 counter on it.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Walking Skyscraper

This spell costs {1} less to cast for each modified creature you control. (Equipment, Auras you control, and counters are modifications.)
Trample
Walking Skyscraper has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)

Command Tower

Tevesh Szat, Doom of Fools

+2: Create two 0/1 black Thrull creature tokens.
+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.
−10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.
Tevesh Szat, Doom of Fools can be your commander.
Partner

Darkwater Catacombs

Kami's Flare

Kami's Flare deals 3 damage to target creature or planeswalker. Kami's Flare also deals 2 damage to that permanent's controller if you control a modified creature. (Equipment, Auras you control, and counters are modifications.)

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Marchesa's Decree

When Marchesa's Decree enters, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Swamp

Lethal Throwdown

As an additional cost to cast this spell, sacrifice a creature or sacrifice a modified creature. (Equipment, Auras you control, and counters are modifications.)
Destroy target creature or planeswalker. If the modified creature was sacrificed, draw a card.

Everglades

Everglades enters tapped.
When Everglades enters, sacrifice it unless you return an untapped Swamp you control to its owner's hand.
{T}: Add {C}{B}.

Grenzo's Cutthroat

First strike
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Myriad Landscape

Myriad Landscape enters 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.

Redcap Heelslasher

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
First strike

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Glen Elendra Archmage

Flying
{U}, Sacrifice Glen Elendra Archmage: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)

Evolving Wilds

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

Kami of Celebration

Whenever a modified creature you control attacks, exile the top card of your library. You may play that card this turn. (Equipment, Auras you control, and counters are modifications.)
Whenever you cast a spell from exile, put a +1/+1 counter on target creature you control.

Blacksnag Buzzard

Flying
Blacksnag Buzzard enters with a +1/+1 counter on it if a creature died this turn.
Plot {1}{B} (You may pay {1}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Death-Greeter's Champion

Dash {3}{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.)
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Double strike

Akki Ember-Keeper

Whenever a nontoken modified creature you control dies, create a 1/1 colorless Spirit creature token. (Equipment, Auras you control, and counters are modifications.)

Leering Onlooker

Flying
{2}{B}{B}, Exile Leering Onlooker from your graveyard: Create two tapped 1/1 black Bat creature tokens with flying.

Fearless Skald

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Double strike

Awoken Demon

Ecstatic Awakener

{2}{B}, Sacrifice another creature: Draw a card, then transform Ecstatic Awakener. Activate only once each turn.

Ecstatic Awakener // Awoken Demon

Dormant Volcano

Dormant Volcano enters tapped.
When Dormant Volcano enters, sacrifice it unless you return an untapped Mountain you control to its owner's hand.
{T}: Add {C}{R}.

Boneyard Desecrator

Menace
{1}{B}, Sacrifice another creature: Put a +1/+1 counter on Boneyard Desecrator. If an outlaw was sacrificed this way, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Rakdos Carnarium

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

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Flame Discharge

Flame Discharge deals X damage to target creature or planeswalker. If you controlled a modified creature as you cast this spell, it deals X plus 2 damage instead. (Equipment, Auras you control, and counters are modifications.)

Rakdos Signet

Frostboil Snarl

As Frostboil Snarl enters, you may reveal an Island or Mountain card from your hand. If you don't, Frostboil Snarl enters tapped.
{T}: Add {U} or {R}.

Dimir Signet

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.

Shadowblood Ridge

Herald of Secret Streams

Creatures you control with +1/+1 counters on them can't be blocked.

Exotic Orchard

Ferrous Lake

Promising Vein

{T}: Add {C}.
{1}, {T}, Sacrifice Promising Vein: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Thrill-Kill Assassin

Deathtouch
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Mountain

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Akki Battle Squad

Whenever one or more modified creatures you control attack, untap all modified creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn. (Equipment, Auras you control, and counters are modifications.)

Marchesa, the Black Rose

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Other creatures you control have dethrone.
Whenever a creature you control with a +1/+1 counter on it dies, return that card to the battlefield under your control at the beginning of the next end step.