Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Island

Arcane Signet

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

Merfolk Traders

When Merfolk Traders enters the battlefield, draw a card, then discard a card.

Palace Familiar

Flying
When Palace Familiar dies, draw a card.

Swamp

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Tidal Bore

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
You may tap or untap target creature.

Lightning Greaves

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

Pongify

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

Zulaport Cutthroat

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

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Mire Triton

Deathtouch
When Mire Triton enters the battlefield, mill two cards and you gain 2 life.

Thassa's Oracle

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Negate

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature.

Baleful Strix

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

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Alexi's Cloak

Flash
Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)

Mission Briefing

Surveil 2, then choose an instant or sorcery card in your graveyard. You may cast it this turn. If that spell would be put into your graveyard, exile it instead. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Salvage Drone

Devoid (This card has no color.)
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)
When Salvage Drone dies, you may draw a card. If you do, discard a card.

Kalastria Healer

Rally — Whenever Kalastria Healer or another Ally enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.

Careful Study

Blacklance Paragon

Flash
When Blacklance Paragon enters the battlefield, target Knight gains deathtouch and lifelink until end of turn.

Unknown Shores

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Ideas Unbound

Draw three cards. Discard three cards at the beginning of the next end step.

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Thornbite Staff

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."
Whenever a Shaman creature enters the battlefield, you may attach Thornbite Staff to it.
Equip {4}

Yarok's Fenlurker

When Yarok's Fenlurker enters the battlefield, each opponent exiles a card from their hand.
{2}{B}: Yarok's Fenlurker gets +1/+1 until end of turn.

Stitcher's Supplier

When Stitcher's Supplier enters the battlefield or dies, mill three cards.

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on the top or bottom of their library.

Dusk Legion Zealot

When Dusk Legion Zealot enters the battlefield, you draw a card and you lose 1 life.

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Sol Ring

Sultai Emissary

When Sultai Emissary dies, manifest the top card of your library. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Silvergill Adept

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}.
When Silvergill Adept enters the battlefield, draw a card.

Oona's Blackguard

Flying
Each other Rogue creature you control enters the battlefield with an additional +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, that player discards a card.

Teferi's Veil

Whenever a creature you control attacks, it phases out at end of combat. (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.)

Merfolk Trickster

Flash
When Merfolk Trickster enters the battlefield, tap target creature an opponent controls. It loses all abilities until end of turn.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Teardrop Kami

Sacrifice Teardrop Kami: You may tap or untap target creature.

Epochrasite

Epochrasite enters the battlefield with three +1/+1 counters on it if you didn't cast it from your hand.
When Epochrasite dies, exile it with three time counters on it and it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may cast this card without paying its mana cost. It has haste.)

Jeering Homunculus

When Jeering Homunculus enters the battlefield, you may goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Command Tower

Altar of Dementia

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

Village Rites

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

Feed the Swarm

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

Lazotep Plating

Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
You and permanents you control gain hexproof until end of turn. (You and they can't be the targets of spells or abilities your opponents control.)

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Blood Artist

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

Fogwalker

Skulk (This creature can't be blocked by creatures with greater power.)
When Fogwalker enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.

Cloud of Faeries

Flying
When Cloud of Faeries enters the battlefield, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Spoils of Blood

Create an X/X black Horror creature token, where X is the number of creatures that died this turn.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Thieves' Guild Enforcer

Flash
Whenever Thieves' Guild Enforcer or another Rogue enters the battlefield under your control, each opponent mills two cards.
As long as an opponent has eight or more cards in their graveyard, Thieves' Guild Enforcer gets +2/+1 and has deathtouch.

Epic Downfall

Exile target creature with mana value 3 or greater.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Undead Augur

Whenever Undead Augur or another Zombie you control dies, you draw a card and you lose 1 life.

Fumble

Return target creature to its owner's hand. Gain control of all Auras and Equipment that were attached to it, then attach them to another creature.

Doomed Dissenter

When Doomed Dissenter dies, create a 2/2 black Zombie creature token.

Floating-Dream Zubera

When Floating-Dream Zubera dies, draw a card for each Zubera that died this turn.

Faerie Miscreant

Flying
When Faerie Miscreant enters the battlefield, if you control another creature named Faerie Miscreant, draw a card.