The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

Orzhov Basilica

Orzhov Basilica enters the battlefield tapped.
When Orzhov Basilica enters the battlefield, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Arcane Signet

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

Necron Monolith

Flying, indestructible
Eternity Gate — Whenever Necron Monolith attacks, mill three cards. For each creature card milled this way, create a 2/2 black Necron Warrior artifact creature token.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Judge of Currents

Whenever a Merfolk you control becomes tapped, you may gain 1 life.

Stonybrook Schoolmaster

Whenever Stonybrook Schoolmaster becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Goliath Truck

Stowage — Whenever Goliath Truck attacks, put two +1/+1 counters on another target attacking creature.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Deeproot Warrior

Whenever Deeproot Warrior becomes blocked, it gets +1/+1 until end of turn.

Reckoner Bankbuster

Reckoner Bankbuster enters the battlefield with three charge counters on it.
{2}, {T}, Remove a charge counter from Reckoner Bankbuster: Draw a card. Then if there are no charge counters on Reckoner Bankbuster, create a Treasure token and a 1/1 colorless Pilot creature token with "This creature crews Vehicles as though its power were 2 greater."
Crew 3

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Merfolk Branchwalker

When Merfolk Branchwalker enters the battlefield, 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.)

Jungle Delver

{3}{G}: Put a +1/+1 counter on Jungle Delver.

Jadelight Ranger

When Jadelight Ranger enters the battlefield, it explores, then it explores again. (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. Then repeat this process.)

Untethered Express

Trample
Whenever Untethered Express attacks, put a +1/+1 counter on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Greasefang, Okiba Boss

At the beginning of combat on your turn, return target Vehicle card from your graveyard to the battlefield. It gains haste. Return it to its owner's hand at the beginning of your next end step.

Knight Paladin

Trample
Rapid-fire Battle Cannon — When Knight Paladin enters the battlefield, it deals 4 damage to each opponent.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters the battlefield tapped unless you control two or more basic lands.

Sol Ring

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Beacon of Immortality

Double target player's life total. Shuffle Beacon of Immortality into its owner's library.

Imperial Recovery Unit

Whenever Imperial Recovery Unit attacks, return target creature or Vehicle card with mana value 2 or less from your graveyard to your hand.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Tishana's Wayfinder

When Tishana's Wayfinder enters the battlefield, 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.)

Daredevil Dragster

At end of combat, if Daredevil Dragster attacked or blocked this combat, put a velocity counter on it. Then if it has two or more velocity counters on it, sacrifice it and draw two cards.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Enchanted Carriage

When Enchanted Carriage enters the battlefield, create two 1/1 white Mouse creature tokens.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Vineshaper Mystic

When Vineshaper Mystic enters the battlefield, put a +1/+1 counter on each of up to two target Merfolk you control.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Summon the School

Create two 1/1 blue Merfolk Wizard creature tokens.
Tap four untapped Merfolk you control: Return Summon the School from your graveyard to your hand.

Skysovereign, Consul Flagship

Flying
Whenever Skysovereign, Consul Flagship enters the battlefield or attacks, it deals 3 damage to target creature or planeswalker an opponent controls.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Deeproot Champion

Whenever you cast a noncreature spell, put a +1/+1 counter on Deeproot Champion.

Aradara Express

Menace
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Tempered Steel

Artifact creatures you control get +2/+2.

Born to Drive

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets +1/+1 for each creature and/or Vehicle you control.
Channel — {2}{W}, Discard Born to Drive: Create two 1/1 colorless Pilot creature tokens with "This creature crews Vehicles as though its power were 2 greater."

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Okiba Salvage

Return target creature or Vehicle card from your graveyard to the battlefield. Then put two +1/+1 counters on that permanent if you control an artifact and an enchantment.

Veteran of the Depths

Whenever Veteran of the Depths becomes tapped, you may put a +1/+1 counter on it.

Aeronaut Admiral

Mech Hangar

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Pilot or Vehicle spell.
{3}, {T}: Target Vehicle becomes an artifact creature until end of turn.

Forest

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Giltgrove Stalker

Giltgrove Stalker can't be blocked by creatures with power 2 or less.

Golgari Rot Farm

Golgari Rot Farm enters the battlefield tapped.
When Golgari Rot Farm enters the battlefield, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Aethersphere Harvester

Flying
When Aethersphere Harvester enters the battlefield, you get {E}{E} (two energy counters).
Pay {E}: Aethersphere Harvester gains lifelink until end of turn.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Reaver Titan

Void Shields — Protection from mana value 3 or less
Gatling Blaster — Whenever Reaver Titan attacks, it deals 5 damage to each opponent.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Bountiful Promenade

Bountiful Promenade enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Lita, Mechanical Engineer

Vigilance
At the beginning of your end step, untap each other artifact creature you control.
{3}{W}, {T}: Create a 5/5 colorless Vehicle artifact token named Zeppelin with flying and crew 3. (It has "Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.")

Fumigate

Destroy all creatures. You gain 1 life for each creature destroyed this way.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Merrow Bonegnawer

{T}: Target player exiles a card from their graveyard.
Whenever you cast a black spell, you may untap Merrow Bonegnawer.

Canoptek Spyder

Flying
Fabricator Claw Array — Whenever another nontoken artifact creature or Vehicle enters the battlefield under your control, draw a card.

Lightning Greaves

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

Peacewalker Colossus

{1}{W}: Another target Vehicle you control becomes an artifact creature until end of turn.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from all colors until end of turn.

Fleetwheel Cruiser

Trample, haste
When Fleetwheel Cruiser enters the battlefield, it becomes an artifact creature until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Forerunner of the Heralds

When Forerunner of the Heralds enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.
Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on Forerunner of the Heralds.

Command Tower

Plains

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
Indatha Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Woodland Cemetery

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Jungleborn Pioneer

When Jungleborn Pioneer enters the battlefield, create a 1/1 blue Merfolk creature token with hexproof. (It can't be the target of spells or abilities your opponents control.)

Fortuitous Find

Choose one or both —
• Return target artifact card from your graveyard to your hand.
• Return target creature card from your graveyard to your hand.

Deeproot Elite

Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on target Merfolk you control.

Undergrowth Stadium

Undergrowth Stadium enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Kumena's Speaker

Kumena's Speaker gets +1/+1 as long as you control another Merfolk or an Island.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Rebbec, Architect of Ascension

Artifacts you control have protection from each mana value among artifacts you control.
Partner (You can have two commanders if both have partner.)

Selesnya Sanctuary

Selesnya Sanctuary enters the battlefield tapped.
When Selesnya Sanctuary enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Harpoon Sniper

{W}, {T}: Harpoon Sniper deals X damage to target attacking or blocking creature, where X is the number of Merfolk you control.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Golden Argosy

Whenever Golden Argosy attacks, exile each creature that crewed it this turn. Return them to the battlefield tapped under their owner's control at the beginning of the next end step.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Armed and Armored

Vehicles you control become artifact creatures until end of turn. Choose a Dwarf you control. Attach any number of Equipment you control to it.

Swamp

Smuggler's Copter

Flying
Whenever Smuggler's Copter attacks or blocks, you may draw a card. If you do, discard a card.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Mechtitan Core

{5}, Exile Mechtitan Core and four other artifact creatures and/or Vehicles you control: Create Mechtitan, a legendary 10/10 Construct artifact creature token with flying, vigilance, trample, lifelink, and haste that's all colors. When that token leaves the battlefield, return all cards exiled with Mechtitan Core except Mechtitan Core to the battlefield tapped under their owners' control.
Crew 2

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Jade Bearer

When Jade Bearer enters the battlefield, put a +1/+1 counter on another target Merfolk you control.

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Cultivator's Caravan

{T}: Add one mana of any color.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)