Emperor Mihail II

You may look at the top card of your library any time.
You may cast Merfolk spells from the top of your library.
Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

Uyo, Silent Prophet

Flying
{2}, Return two lands you control to their owner's hand: Copy target instant or sorcery spell. You may choose new targets for the copy.

Alandra, Sky Dreamer

Whenever you draw your second card each turn, create a 2/2 blue Drake creature token with flying.
Whenever you draw your fifth card each turn, Alandra, Sky Dreamer and Drakes you control each get +X/+X until end of turn, where X is the number of cards in your hand.

Orvar, the All-Form

Changeling
Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.
When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Quicksilver Gargantuan

You may have Quicksilver Gargantuan enter as a copy of any creature on the battlefield, except it's 7/7.

Windrider Patrol

Flying
Whenever Windrider Patrol deals combat damage to a player, 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.)

River Sneak

River Sneak can't be blocked.
Whenever another Merfolk you control enters, River Sneak gets +1/+1 until end of turn.

Triton Wavebreaker

Bestow {1}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
As long as Triton Wavebreaker is a creature, it has prowess. (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Enchanted creature gets +1/+1 and has prowess.

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Sage of the Falls

Whenever Sage of the Falls or another non-Human creature you control enters, you may draw a card. If you do, discard a 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, draw a card.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Salvager of Secrets

When Salvager of Secrets enters, return target instant or sorcery card from your graveyard to your hand.

Soothsayer Adept

{1}{U}, {T}: Draw a card, then discard a card.

Shipwreck Dowser

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

Moonlit Scavengers

When Moonlit Scavengers enters, if you control an artifact or enchantment, return target creature an opponent controls to its owner's hand.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Slinn Voda, the Rising Deep

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
When Slinn Voda, the Rising Deep enters, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

Benthic Criminologists

Whenever Benthic Criminologists enters or attacks, you may sacrifice an artifact. If you do, draw a card.

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

Svyelun of Sea and Sky

Svyelun of Sea and Sky has indestructible as long as you control at least two other Merfolk.
Whenever Svyelun attacks, draw a card.
Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Merfolk Pupil

When Merfolk Pupil enters, draw a card, then discard a card.
{1}{U}, Exile Merfolk Pupil from your graveyard: Draw a card, then discard a card.

Saltwater Stalwart

Whenever Saltwater Stalwart deals damage to an opponent, target player draws a card.

Watertrap Weaver

When Watertrap Weaver enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Mistral Singer

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Expedition Diviner

Flying
As long as you control another Wizard, Expedition Diviner has "When this creature dies, draw a card."

Cleric of Chill Depths

Whenever Cleric of Chill Depths blocks a creature, that creature doesn't untap during its controller's next untap step.

Tazeem Roilmage

Kicker {4} (You may pay an additional {4} as you cast this spell.)
When Tazeem Roilmage enters, if it was kicked, return target instant or sorcery card from your graveyard to your hand.

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Octoprophet

When Octoprophet 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.)

Unauthorized Exit

Return target nonland permanent to its owner's hand. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dazzling Lights

Target creature gets -3/-0 until end of turn.
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.)

Soporific Springs

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

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Arrester's Admonition

Return target creature to its owner's hand.
Addendum — If you cast this spell during your main phase, draw a card.

Negate

Out of Air

This spell costs {2} less to cast if it targets a creature spell.
Counter target spell.

Quick Study

Soul Read

Choose one —
• Counter target spell unless its controller pays {4}.
• Draw two cards.

Cancel

Frantic Inventory

Draw a card, then draw cards equal to the number of cards named Frantic Inventory in your graveyard.

Reliquary Tower

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

Cone of Cold

Roll a d20.
1—9 | Tap all creatures your opponents control.
10—19 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps.
20 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps. Until your next turn, creatures your opponents control enter tapped.

Mists of Lórien

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Return target nonland permanent and each other nonland permanent with the same mana value as that permanent to their owners' hands.

Spellbook

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Golden Egg

When Golden Egg enters, draw a card.
{1}, {T}, Sacrifice Golden Egg: Add one mana of any color.
{2}, {T}, Sacrifice Golden Egg: You gain 3 life.

Island

Captivating Cave

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice Captivating Cave: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Deliberate

Shell Shield

Kicker {1} (You may pay an additional {1} as you cast this spell.)
Target creature you control gets +0/+3 until end of turn. If this spell was kicked, that creature also gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Synchronized Eviction

This spell costs {2} less to cast if you control at least two creatures that share a creature type.
Put target nonland permanent into its owner's library second from the top.

Counterspell

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When Capture Sphere enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Bubble Snare

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
Enchant creature
When Bubble Snare enters, if it was kicked, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Dramatic Accusation

Enchant creature
When Dramatic Accusation enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{U}{U}: Shuffle enchanted creature into its owner's library.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

One With the Wind

Enchant creature
Enchanted creature gets +2/+2 and has flying.

Extraordinary Journey

When Extraordinary Journey enters, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Crashing Tide

This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.

Field Research

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
Draw two cards. If this spell was kicked, draw three cards instead.

Unexplained Vision

Draw three cards.
Adamant — If at least three blue mana was spent to cast this spell, scry 3.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Iceberg Titan

Whenever Iceberg Titan attacks, you may tap or untap target artifact or creature.

Inverted Iceberg

When Inverted Iceberg enters, mill a card, then draw a card. (To mill a card, put the top card of your library into your graveyard.)
Craft with artifact {4}{U}{U} ({4}{U}{U}, Exile this artifact, Exile another artifact you control or an artifact card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Inverted Iceberg // Iceberg Titan

Pristine Talisman

Mantle of Tides

Equipped creature gets +1/+2.
Whenever you draw your second card each turn, attach Mantle of Tides to target creature you control.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Bubble Smuggler

Disguise {5}{U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
As Bubble Smuggler is turned face up, put four +1/+1 counters on it.

Drake

Merfolk

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Replicated Ring

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

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.)