Have

Steam Vents

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

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Thought Sponge

Flash
Thought Sponge enters 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.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Grishnákh, Brash Instigator

When Grishnákh, Brash Instigator enters, amass Orcs 2. When you do, until end of turn, gain control of target nonlegendary creature an opponent controls with power less than or equal to the amassed Army's power. Untap that creature. It gains haste until end of turn.

Unspeakable Symbol

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

Flayer of the Hatebound

Undying (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.)
Whenever Flayer of the Hatebound or another creature enters from your graveyard, that creature deals damage equal to its power to any target.

Shivan Reef

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

Volrath's Stronghold

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

Cytoplast Manipulator

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{U}, {T}: Gain control of target creature with a +1/+1 counter on it for as long as Cytoplast Manipulator remains on the battlefield.

Underground River

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

Scorn-Blade Berserker

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.)
{1}, Sacrifice this creature: Draw a card.

Izzet Signet

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.

Zealous Conscripts

Haste
When Zealous Conscripts enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Spawning Pit

Sacrifice a creature: Put a charge counter on Spawning Pit.
{1}, Remove two charge counters from Spawning Pit: Create a 2/2 colorless Spawn artifact creature token.

Fellwar Stone

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

Morphic Pool

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

Disciple of Bolas

When Disciple of Bolas enters, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Rakdos Signet

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Bloodthrone Vampire

Sacrifice a creature: Bloodthrone Vampire gets +2/+2 until end of turn.

Danny Pink

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

Domineering Will

Target player gains control of up to three target nonattacking creatures until end of turn. Untap those creatures. They block this turn if able.

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Blazemire Verge

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

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Legate Lanius, Caesar's Ace

Decimate — When Legate Lanius enters, each opponent sacrifices a tenth of the creatures they control of their choice, rounded up.
Whenever an opponent sacrifices a creature, put a +1/+1 counter on Legate Lanius.

Morbid Opportunist

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

Sulfurous Springs

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

Mob Rule

Choose one —
• Gain control of all creatures with power 4 or greater until end of turn. Untap those creatures. They gain haste until end of turn.
• Gain control of all creatures with power 3 or less until end of turn. Untap those creatures. They gain haste until end of turn.

Training Center

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

Mind Flayer

Dominate Monster — When Mind Flayer enters, gain control of target creature for as long as you control Mind Flayer.

Gloomlake Verge

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

Junji, the Midnight Sky

Flying, menace
When Junji, the Midnight Sky dies, choose one —
• Each opponent discards two cards and loses 2 life.
• Put target non-Dragon creature card from a graveyard onto the battlefield under your control. You lose 2 life.

Mahadi, Emporium Master

At the beginning of your end step, create a Treasure token for each creature that died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ashnod's Altar

Kari Zev's Expertise

Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
You may cast a spell with mana value 2 or less from your hand without paying its mana cost.

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.)

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.

Talisman of Dominance

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

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Coercive Recruiter

Whenever Coercive Recruiter or another Pirate you control enters, gain control of target creature until end of turn. Untap that creature. Until end of turn, it gains haste and becomes a Pirate in addition to its other types.

Dimir Signet

Blasphemous Act

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

Satoru, the Infiltrator

Menace
Whenever Satoru, the Infiltrator and/or one or more other nontoken creatures you control enter, if none of them were cast or no mana was spent to cast them, draw a card.

Island

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.

Graven Cairns

{T}: Add {C}.
{B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Kalain, Reclusive Painter

When Kalain, Reclusive Painter enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Other creatures you control enter with an additional +1/+1 counter on them for each mana from a Treasure spent to cast them.

Command Tower

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

Uncivil Unrest

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)
If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Dragonskull Summit

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

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

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.

Negate

Disciple of Griselbrand

{1}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Sulfur Falls

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

Kethek, Crucible Goliath

At the beginning of your end step, you may sacrifice another creature. If you do, reveal cards from the top of your library until you reveal a nonlegendary creature card with lesser mana value, put it onto the battlefield, then put the rest on the bottom of your library in a random order.

Feign Death

Talisman of Indulgence

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

Mountain

Blood Crypt

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

Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.

Watery Grave

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

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Talisman of Creativity

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

Viscera Seer

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

Swamp

Drowned Catacomb

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

Sol Ring

Village Rites

Spellskite

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

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Vigean Graftmage

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{1}{U}: Untap target creature with a +1/+1 counter on it.

Counterspell

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Arcane Signet

Into the Pit

You may look at the top card of your library any time.
You may cast spells from the top of your library by sacrificing a nonland permanent in addition to paying their other costs.

Gev, Scaled Scorch

Ward—Pay 2 life.
Other creatures you control enter with an additional +1/+1 counter on them for each opponent who lost life this turn.
Whenever you cast a Lizard spell, Gev, Scaled Scorch deals 1 damage to target opponent.

Sower of Temptation

Flying
When Sower of Temptation enters, gain control of target creature for as long as Sower of Temptation remains on the battlefield.

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.")