Tune the Narrative

Draw a card. You get {E}{E} (two energy counters).

Electrozoa

Flash
Flying
When Electrozoa enters the battlefield, you get {E}{E} (two energy counters).
At the beginning of your precombat main phase, tap Electrozoa unless you pay {E}.

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Roil Cartographer

Landfall — Whenever a land enters the battlefield under your control, you get {E} (an energy counter).
{T}, Pay six {E}: Draw three cards.

Volshe Tideturner

{T}: Add {U}. Spend this mana only to cast an instant or sorcery spell or a kicked spell.

Aether Spike

Choose target spell. You get {E}{E} (two energy counters), then you may pay any amount of {E}. Counter that spell unless its controller pays {1} for each {E} paid this way.

Coral Merfolk

Merfolk of the Pearl Trident

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.

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}.)

Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Tide Shaper

Kicker {1} (You may pay an additional {1} as you cast this spell.)
When Tide Shaper enters the battlefield, if it was kicked, target land becomes an Island for as long as Tide Shaper remains on the battlefield.
Tide Shaper gets +1/+1 as long as an opponent controls an Island.

Benthic Criminologists

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

Gray Harbor Merfolk

Gray Harbor Merfolk can't be blocked.
Gray Harbor Merfolk gets +2/+0 as long as you control a commander that's a creature or planeswalker.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Harbinger of the Seas

Mistway Spy

Flying
Disguise {1}{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.)
When Mistway Spy is turned face up, until end of turn, whenever a creature you control deals combat damage to a player, investigate.

Step Through

Return two target creatures to their owners' hands.
Wizardcycling {2} ({2}, Discard this card: Search your library for a Wizard card, reveal it, put it into your hand, then shuffle.)

Voda Sea Scavenger

Domain — When Voda Sea Scavenger enters the battlefield, look at the top X cards of your library, where X is the number of basic land types among lands you control. You may put one of those cards on top of your library. Put the rest on the bottom of your library in a random order.

Furtive Courier

Furtive Courier can't be blocked as long as you've sacrificed an artifact this turn.
Whenever Furtive Courier attacks, draw a card, then discard a card.

Tempest Harvester

When Tempest Harvester enters the battlefield, you get {E}{E} (two energy counters).
{T}, Pay {E}: Draw a card, then discard a card.

Merfolk Coralsmith

{1}: Merfolk Coralsmith gets +1/-1 until end of turn.
When Merfolk Coralsmith dies, scry 2.

Soothsayer Adept

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

Solar Transformer

Solar Transformer enters the battlefield tapped.
When Solar Transformer enters the battlefield, you get {E}{E}{E} (three energy counters).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Raving Visionary

{U}, {T}: Draw a card, then discard a card.
Delirium — {2}{U}, {T}: Draw a card. Activate only if there are four or more card types among cards in your graveyard.

Bespoke Battlewagon

{T}: You get {E}{E} (two energy counters).
{T}, Pay {E}{E}: Tap target creature.
{T}, Pay {E}{E}{E}: Draw a card.
Pay {E}{E}{E}{E}: Bespoke Battlewagon becomes an artifact creature until end of turn.
Crew 4