Merrow Commerce

At the beginning of your end step, untap all Merfolk you control.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Tidal Courier

When Tidal Courier enters, reveal the top four cards of your library. Put all Merfolk cards revealed this way into your hand and the rest on the bottom of your library in any order.
{3}{U}: Tidal Courier gains flying until end of turn.

Braingeyser

Exile

Exile target nonwhite attacking creature. You gain life equal to its toughness.

Plains

Overlord of the Floodpits

Impending 4—{1}{U}{U} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Flying
Whenever Overlord of the Floodpits enters or attacks, draw two cards, then discard a card.

Azorius Locket

{T}: Add {W} or {U}.
{W/U}{W/U}{W/U}{W/U}, {T}, Sacrifice Azorius Locket: Draw two cards.

Spires of Orazca

(Transforms from Thaumatic Compass.)
{T}: Add {C}.
{T}: Untap target attacking creature an opponent controls and remove it from combat.

Thaumatic Compass

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
At the beginning of your end step, if you control seven or more lands, transform Thaumatic Compass.

Thaumatic Compass // Spires of Orazca

Tempest Caller

When Tempest Caller enters, tap all creatures target opponent controls.

Hot Soup

Equipped creature can't be blocked.
Whenever equipped creature is dealt damage, destroy it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Brago, King Eternal

Flying
Whenever Brago, King Eternal deals combat damage to a player, exile any number of target nonland permanents you control, then return those cards to the battlefield under their owner's control.

Frost Trickster

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

Command Tower

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

Sharae of Numbing Depths

When Sharae of Numbing Depths enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you tap one or more untapped creatures your opponents control, draw a card. This ability triggers only once each turn.

Dovin's Dismissal

Put up to one target tapped creature on top of its owner's library. You may search your library and/or graveyard for a card named Dovin, Architect of Law, reveal it, and put it into your hand. If you search your library this way, shuffle.

Azorius Cluestone

{T}: Add {W} or {U}.
{W}{U}, {T}, Sacrifice Azorius Cluestone: Draw a card.

Reliquary Tower

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

No More Lies

Counter target spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Sphinx's Revelation

Storm Sculptor

Storm Sculptor can't be blocked.
When Storm Sculptor enters, return a creature you control to its owner's hand.

True-Name Nemesis

As True-Name Nemesis enters, choose a player.
True-Name Nemesis has protection from the chosen player.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Breakthrough

Draw four cards, then choose X cards in your hand and discard the rest.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Ojutai's Command

Choose two —
• Return target creature card with mana value 2 or less from your graveyard to the battlefield.
• You gain 4 life.
• Counter target creature spell.
• Draw a card.

Abjure

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

Deepchannel Mentor

Blue creatures you control can't be blocked.

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Sol Ring

Solemn Offering

Destroy target artifact or enchantment. You gain 4 life.

Counterspell

Dovin, Architect of Law

+1: You gain 2 life and draw a card.
−1: Tap target creature. It doesn't untap during its controller's next untap step.
−9: Tap all permanents target opponent controls. That player skips their next untap step.

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Guidestone Compass

{1}, {T}: Target creature you control explores. Activate only as a sorcery. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Lodestone Needle

Flash
When Lodestone Needle enters, tap up to one target artifact or creature and put two stun counters on it.
Craft with artifact {2}{U} ({2}{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.)

Lodestone Needle // Guidestone Compass

Harbinger of the Tides

You may cast this card as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When this creature enters, you may return target tapped creature an opponent controls to its owner's hand.

Call to Mind

Return target instant or sorcery card from your graveyard to your hand.

Solemn Simulacrum

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

River Herald Scout

When River Herald Scout enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Coveted Jewel

When Coveted Jewel enters, draw three cards.
{T}: Add three mana of any one color.
Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of Coveted Jewel. Untap it.

Permission Denied

Counter target noncreature spell. Your opponents can't cast noncreature spells this turn.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

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.

Tishana's Tidebinder

Flash
When Tishana's Tidebinder enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

Augur of Bolas

When Augur of Bolas 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.

Ancestral Vision

Suspend 4—{U} (Rather than cast this card from your hand, pay {U} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Target player draws three cards.

Seahunter

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Merrow Reejerey

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Snow-Covered Island

Merfolk Wayfinder

Flying
When Merfolk Wayfinder enters, reveal the top three cards of your library. Put all Island cards revealed this way into your hand and the rest on the bottom of your library in any order.

Salvager of Secrets

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

Island

Tidespout Tyrant

Flying
Whenever you cast a spell, return target permanent to its owner's hand.

Sphinx's Insight

Draw two cards.
Addendum — If you cast this spell during your main phase, you gain 2 life.

Floodpits Drowner

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

Moonlit Scavengers

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

Sanctum of the Sun

(Transforms from Azor's Gateway.)
{T}: Add X mana of any one color, where X is your life total.

Azor's Gateway

{1}, {T}: Draw a card, then exile a card from your hand. If cards with five or more different mana values are exiled with Azor's Gateway, you gain 5 life, untap Azor's Gateway, and transform it.

Azor's Gateway // Sanctum of the Sun

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Aetherize

Return all attacking creatures to their owner's hand.

Snow-Covered Plains

Render Silent

Counter target spell. Its controller can't cast spells this turn.

Merfolk Trickster

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

Moonsilver Spear

Equipped creature has first strike.
Whenever equipped creature attacks, create a 4/4 white Angel creature token with flying.
Equip {4}

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Dovin's Acuity

When Dovin's Acuity enters, you gain 2 life and draw a card.
Whenever you cast an instant spell during your main phase, you may return Dovin's Acuity to its owner's hand.

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

Merrow Harbinger

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
When Merrow Harbinger enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Watertrap Weaver

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