Opportunity

Aegis Turtle

Expendable Lackey

{1}{U}, Exile this card from your graveyard: Create a 1/1 blue Fish creature token with "This token can't be blocked." Activate only as a sorcery.

Clammy Prowler

Whenever this creature attacks, another target attacking creature can't be blocked this turn.

Corsairs of Umbar

{2}{U}: Target Goblin, Orc, or Pirate can't be blocked this turn.
Whenever this creature deals combat damage to a player, amass Orcs 3. (Put three +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Arcane Epiphany

This spell costs {1} less to cast if you control a Wizard.
Draw three cards.

Illvoi Operative

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Utter Insignificance

Flash
Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.
{2}{C}: Exile enchanted creature.

Reef Worm

When this creature dies, create a 3/3 blue Fish creature token with "When this token dies, create a 6/6 blue Whale creature token with 'When this token dies, create a 9/9 blue Kraken creature token.'"

Mindwhisker

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Threshold — As long as seven or more cards are in your graveyard, creatures your opponents control get -1/-0.

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Serum Visionary

When this creature enters, draw a card, then scry 2.

Breaker of Creation

When you cast this spell, you gain 1 life for each colorless permanent you control.
Hexproof from each color
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)

Saruman the White

Ward {2}
Whenever you cast your second spell each turn, amass Orcs 2. (Put two +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Surrounded by Orcs

Amass Orcs 3, then target player mills X cards, where X is the amassed Army's power. (To amass Orcs 3, put three +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Locked in the Cemetery

Enchant creature
When this Aura enters, if there are five or more cards in your graveyard, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Starlight Snare

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Synth Infiltrator

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
You may have this creature enter as a copy of any creature on the battlefield, except it's a Synth artifact creature in addition to its other types.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Floodpits Drowner

Flash
Vigilance
When this creature enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

Essence Scatter

Aether Channeler

When this creature 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.

Uthros Psionicist

The second spell you cast each turn costs {2} less to cast.

Deceive the Messenger

Target creature gets -3/-0 until end of turn.
Amass Orcs 1. (Put a +1/+1 counter on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Chilling Trap

Target creature gets -4/-0 until end of turn. If you control a Wizard, draw a card.

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sphinx of the Second Sun

Flying
At the beginning of each of your postcombat main phases, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)

Storm of Saruman

Ward {3}
Whenever you cast your second spell each turn, copy it, except the copy isn't legendary. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Petrifying Meddler

Devoid (This card has no color.)
When you cast this spell, tap up to one target creature and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Reach

Copycrook

You may have this creature enter as a copy of any creature on the battlefield, except it has "Whenever this creature attacks, it connives." (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Illvoi Infiltrator

This creature can't be blocked if you've cast two or more spells this turn.
Whenever this creature deals combat damage to a player, draw a card.

Duskmourn's Domination

Enchant creature
You control enchanted creature.
Enchanted creature gets -3/-0 and loses all abilities.

Phase Dolphin

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Wall of Lost Thoughts

Defender (This creature can't attack.)
When this creature enters, target player mills four cards. (They put the top four cards of their library into their graveyard.)

Hithlain Knots

Tap target creature. Scry 1.
Draw a card.

Spellgyre

Choose one —
• Counter target spell.
• Surveil 2, then draw two cards. (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.)

Fleeting Distraction

Target creature gets -1/-0 until end of turn.
Draw a card.

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Island

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Aven Eternal

Flying
When this creature enters, 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.)

Take the Fall

Target creature gets -1/-0 until end of turn. It gets -4/-0 until end of turn instead if you control an outlaw. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Draw a card.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Waker of Waves

Creatures your opponents control get -1/-0.
{1}{U}, Discard this card: Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Emrakul's Messenger

Devoid (This card has no color.)
Flying
Whenever you draw your second card each turn, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this token: Add {C}."

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Faerie Seer

Flying
When this creature enters, 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.)

Don't Make a Sound

Counter target spell unless its controller pays {2}. If they do, 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.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Eddymurk Crab

Flash
This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
This creature enters tapped if it's not your turn.
When this creature enters, tap up to two target creatures.

Omenspeaker

When this creature enters, 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.)

Razzle-Dazzler

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. It can't be blocked this turn.

Corrupted Shapeshifter

Devoid (This card has no color.)
As this creature enters, it becomes your choice of a 3/3 creature with flying, a 2/5 creature with vigilance, or a 0/12 creature with defender.

Plumecreed Escort

Flash
Flying
When this creature enters, target creature you control gains hexproof until end of turn.

Jailbreak Scheme

Spree (Choose one or more additional costs.)
+ {3} — Put a +1/+1 counter on target creature. It can't be blocked this turn.
+ {2} — Target artifact or creature's owner puts it on their choice of the top or bottom of their library.

Whirler Rogue

When this creature enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Cancel

Mischievous Mystic

Flying
Whenever you draw your second card each turn, create a 1/1 blue Faerie creature token with flying.

Aven Wind Mage

Flying
Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn.

Augur of Bolas

When this creature enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Erudite Wizard

Whenever you draw your second card each turn, put a +1/+1 counter on this creature.

Hydroelectric Laboratory

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

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

Saruman's Trickery

Counter target spell.
Amass Orcs 1. (Put a +1/+1 counter on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Naban, Dean of Iteration

If a Wizard you control entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Murder of Crows

Flying
Whenever another creature dies, you may draw a card. If you do, discard a card.

Depth Defiler

Devoid (This card has no color.)
Kicker {C} (You may pay an additional {C} as you cast this spell.)
When you cast this spell, choose one. If it was kicked, choose both instead.
• Return target creature to its owner's hand.
• Target player draws two cards, then discards a card.