Counterspell

Sol Ring

Priest of Gix

When Priest of Gix enters the battlefield, add {B}{B}{B}.

Vivid Meadow

Vivid Meadow enters the battlefield tapped with two charge counters on it.
{T}: Add {W}.
{T}, Remove a charge counter from Vivid Meadow: Add one mana of any color.

Vivid Marsh

Vivid Marsh enters the battlefield tapped with two charge counters on it.
{T}: Add {B}.
{T}, Remove a charge counter from Vivid Marsh: Add one mana of any color.

Aetherwind Basker

Trample
Whenever Aetherwind Basker enters the battlefield or attacks, you get {E} (an energy counter) for each creature you control.
Pay {E}: Aetherwind Basker gets +1/+1 until end of turn.

Servant of the Conduit

When Servant of the Conduit enters the battlefield, you get {E}{E} (two energy counters).
{T}, Pay {E}: Add one mana of any color.

Demon of Dark Schemes

Flying
When Demon of Dark Schemes enters the battlefield, all other creatures get -2/-2 until end of turn.
Whenever another creature dies, you get {E} (an energy counter).
{2}{B}, Pay {E}{E}{E}{E}: Put target creature card from a graveyard onto the battlefield under your control tapped.

Live Fast

You draw two cards, lose 2 life, and get {E}{E} (two energy counters).

Ezuri, Stalker of Spheres

When Ezuri, Stalker of Spheres enters the battlefield, you may pay {3}. If you do, proliferate twice.
Whenever you proliferate, draw a card.

Arcane Sanctum

Arcane Sanctum enters the battlefield tapped.
{T}: Add {W}, {U}, or {B}.

Fabrication Module

Whenever you get one or more {E} (energy counters), put a +1/+1 counter on target creature you control.
{4}, {T}: You get {E}.

Aethersquall Ancient

Flying
At the beginning of your upkeep, you get {E}{E}{E} (three energy counters).
Pay {E}{E}{E}{E}{E}{E}{E}{E}: Return all other creatures to their owners' hands. Activate only as a sorcery.

Dovin's Veto

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

Plains

Chthonian Nightmare

When Chthonian Nightmare enters the battlefield, you get {E}{E}{E} (three energy counters).
Pay X {E}, Sacrifice a creature, Return Chthonian Nightmare to its owner's hand: Return target creature card with mana value X from your graveyard to the battlefield. Activate only as a sorcery.

Electrostatic Pummeler

When Electrostatic Pummeler enters the battlefield, you get {E}{E}{E} (three energy counters).
Pay {E}{E}{E}: Electrostatic Pummeler gets +X/+X until end of turn, where X is its power.

Architect of the Untamed

Landfall — Whenever a land enters the battlefield under your control, you get {E} (an energy counter).
Pay {E}{E}{E}{E}{E}{E}{E}{E}: Create a 6/6 colorless Beast artifact creature token.

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Aether Poisoner

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Aether Poisoner enters the battlefield, you get {E}{E} (two energy counters).
Whenever Aether Poisoner attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

Steady Progress

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Aetherworks Marvel

Whenever a permanent you control is put into a graveyard, you get {E} (an energy counter).
{T}, Pay {E}{E}{E}{E}{E}{E}: Look at the top six cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Decoction Module

Whenever a creature enters the battlefield under your control, you get {E} (an energy counter).
{4}, {T}: Return target creature you control to its owner's hand.

Swords to Plowshares

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

Thriving Turtle

When Thriving Turtle enters the battlefield, you get {E}{E} (two energy counters).
Whenever Thriving Turtle attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Vivid Creek

Vivid Creek enters the battlefield tapped with two charge counters on it.
{T}: Add {U}.
{T}, Remove a charge counter from Vivid Creek: Add one mana of any color.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Forest

Reliquary Tower

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

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on Soulherder.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Consulate Surveillance

When Consulate Surveillance enters the battlefield, you get {E}{E}{E}{E} (four energy counters).
Pay {E}{E}: Prevent all damage that would be dealt to you this turn by a source of your choice.

Aetherstorm Roc

Flying
Whenever Aetherstorm Roc or another creature enters the battlefield under your control, you get {E} (an energy counter).
Whenever Aetherstorm Roc attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Evolution Sage

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Automated Assembly Line

Whenever one or more artifact creatures you control deal combat damage to a player, you get {E} (an energy counter).
Pay {E}{E}{E}: Create a tapped 3/3 colorless Robot artifact creature token.

Vivid Grove

Vivid Grove enters the battlefield tapped with two charge counters on it.
{T}: Add {G}.
{T}, Remove a charge counter from Vivid Grove: Add one mana of any color.

Island

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Multiform Wonder

When Multiform Wonder enters the battlefield, you get {E}{E}{E} (three energy counters).
Pay {E}: Multiform Wonder gains your choice of flying, vigilance, or lifelink until end of turn.
Pay {E}: Multiform Wonder gets +2/-2 or -2/+2 until end of turn.

Highspire Infusion

Target creature gets +3/+3 until end of turn. You get {E}{E} (two energy counters).

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Aethergeode Miner

Whenever Aethergeode Miner attacks, you get {E}{E} (two energy counters).
Pay {E}{E}: Exile Aethergeode Miner, then return it to the battlefield under its owner's control.

Confiscation Coup

Choose target artifact or creature. You get {E}{E}{E}{E} (four energy counters), then you may pay an amount of {E} equal to that permanent's mana value. If you do, gain control of it.

Shielded Aether Thief

Flash (You may cast this spell any time you could cast an instant.)
Whenever Shielded Aether Thief blocks, you get {E} (an energy counter).
{T}, Pay {E}{E}{E}: Draw a card.

Command Tower

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

Arcane Signet

Attune with Aether

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You get {E}{E} (two energy counters).

Swamp

Brokers Confluence

Choose three. You may choose the same mode more than once.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
• Target creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
• Counter target activated or triggered ability.

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Scheming Aspirant

Whenever you proliferate, each opponent loses 2 life and you gain 2 life.

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."

Yarok, the Desecrated

Deathtouch, lifelink
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Sentry Bot

Flash
This spell costs {1} less to cast for each creature attacking you.
When Sentry Bot enters the battlefield, you get {E} for each creature attacking you.
At the beginning of combat on your turn, you may pay {E}{E}{E}. If you do, put a +1/+1 counter on each creature you control.

Glint-Sleeve Siphoner

Menace
Whenever Glint-Sleeve Siphoner enters the battlefield or attacks, you get {E} (an energy counter).
At the beginning of your upkeep, you may pay {E}{E}. If you do, you draw a card and you lose 1 life.

Brotherhood Scribe

Metalcraft — {T}: You get {E} (an energy counter). Activate only if you control three or more artifacts.
Whenever you get one or more {E} during your turn, creatures you control get +1/+1 until end of turn.

Peema Aether-Seer

When Peema Aether-Seer enters the battlefield, you get an amount of {E} (energy counters) equal to the greatest power among creatures you control.
Pay {E}{E}{E}: Target creature blocks this turn if able.

Longtusk Cub

Whenever Longtusk Cub deals combat damage to a player, you get {E}{E} (two energy counters).
Pay {E}{E}: Put a +1/+1 counter on Longtusk Cub.

Bristling Hydra

When Bristling Hydra enters the battlefield, you get {E}{E}{E} (three energy counters).
Pay {E}{E}{E}: Put a +1/+1 counter on Bristling Hydra. It gains hexproof until end of turn.

Opulent Palace

Opulent Palace enters the battlefield tapped.
{T}: Add {B}, {G}, or {U}.

Fellwar Stone

Glimmer of Genius

Scry 2, then draw two cards. You get {E}{E} (two energy counters).

Sandsteppe Citadel

Sandsteppe Citadel enters the battlefield tapped.
{T}: Add {W}, {B}, or {G}.

Rogue Refiner

When Rogue Refiner enters the battlefield, draw a card and you get {E}{E} (two energy counters).

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.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mortify

Chromatic Lantern

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

Rex, Cyber-Hound

Whenever Rex, Cyber-Hound deals combat damage to a player, they mill two cards and you get {E}{E} (two energy counters).
Pay {E}{E}: Choose target creature card in a graveyard. Exile it with a brain counter on it. Activate only as a sorcery.
Rex has all activated abilities of all cards in exile with brain counters on them.

Reject Imperfection

Counter target spell. If that spell's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Winding Constrictor

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.