Architect of the Untamed

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

Arcane Signet

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

Tune the Narrative

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

Electrosiphon

Counter target spell. You get an amount of {E} (energy counters) equal to its mana value.

Cayth, Famed Mechanist

Fabricate 1 (When this creature enters the battlefield, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)
Other nontoken creatures you control have fabricate 1.
{2}, {T}: Choose one —
• Populate.
• Proliferate.

Deadlock Trap

Deadlock Trap enters the battlefield tapped.
When Deadlock Trap enters the battlefield, you get {E}{E} (two energy counters).
{T}, Pay {E}: Tap target creature or planeswalker. Its activated abilities can't be activated this turn.

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.

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).

Izzet Generatorium

If you would get one or more {E} (energy counters), you get that many plus one {E} instead.
{T}: Draw a card. Activate only if you've paid or lost four or more {E} this turn.

Wheel of Potential

You get {E}{E}{E} (three energy counters), then you may pay X {E}.
Each player may exile their hand and draw X cards. If X is 7 or more, you may play cards you own exiled this way until the end of your next turn.

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.

Assaultron Dominator

When Assaultron Dominator enters the battlefield, you get {E}{E} (two energy counters).
Whenever an artifact creature you control attacks, you may pay {E}. If you do, put your choice of a +1/+1, first strike, or trample counter on that creature.

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.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Animation Module

Whenever one or more +1/+1 counters are put on a permanent you control, you may pay {1}. If you do, create a 1/1 colorless Servo artifact creature token.
{3}, {T}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

HELIOS One

{T}: Add {C}.
{1}, {T}: You get {E} (an energy counter).
{3}, {T}, Pay X {E}, Sacrifice HELIOS One: Destroy target nonland permanent with mana value X. Activate only as a sorcery.

Rogue Refiner

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

Contentious Plan

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

Volatile Stormdrake

Flying, hexproof from activated and triggered abilities
When Volatile Stormdrake enters the battlefield, exchange control of Volatile Stormdrake and target creature an opponent controls. If you do, you get {E}{E}{E}{E}, then sacrifice that creature unless you pay an amount of {E} equal to its mana value.

Voltaic Brawler

When Voltaic Brawler enters the battlefield, you get {E}{E} (two energy counters).
Whenever Voltaic Brawler attacks, you may pay {E}. If you do, it gets +1/+1 and gains trample until end of turn.

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.)

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.

Crackling Falls

Crackling Falls enters the battlefield tapped.
{T}: Add {U} or {R}.

Rush of Inspiration

Draw two cards. Then discard a card at random unless you pay {E}{E} (two energy counters).

Rush of Inspiration // Crackling Falls

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.)

Omnath, Locus of Creation

When Omnath, Locus of Creation enters the battlefield, draw a card.
Landfall — Whenever a land enters the battlefield under your control, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

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.)

Aethertide Whale

Flying
When Aethertide Whale enters the battlefield, you get six {E} (energy counters).
Pay {E}{E}{E}{E}: Return Aethertide Whale to its owner's hand.

Glimmer of Genius

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

Dr. Madison Li

Whenever you cast an artifact spell, you get {E} (an energy counter).
{T}, Pay {E}: Target creature gets +1/+0 and gains trample and haste until end of turn.
{T}, Pay {E}{E}{E}: Draw a card.
{T}, Pay {E}{E}{E}{E}{E}: Return target artifact card from your graveyard to the battlefield tapped.

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}.

Tekuthal, Inquiry Dominus

Flying
If you would proliferate, proliferate twice instead.
{1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal, Inquiry Dominus. ({U/P} can be paid with either {U} or 2 life.)

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Aether Hub

When Aether Hub enters the battlefield, you get {E} (an energy counter).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

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.

Era of Innovation

Whenever an artifact or Artificer enters the battlefield under your control, you may pay {1}. If you do, you get {E}{E} (two energy counters).
Pay six {E}, Sacrifice Era of Innovation: Draw three cards.

Primal Prayers

When Primal Prayers enters the battlefield, you get {E}{E} (two energy counters).
You may cast creature spells with mana value 3 or less by paying {E} rather than paying their mana costs. If you cast a spell this way, you may cast it as though it had flash.

Wrath of the Skies

You get X {E} (energy counters), then you may pay any amount of {E}. Destroy each artifact, creature, and enchantment with mana value less than or equal to the amount of {E} paid this way.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering the battlefield don't cause abilities of permanents your opponents control to trigger.

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.)

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.

Birds of Paradise

The Motherlode, Excavator

When The Motherlode, Excavator enters the battlefield, choose target opponent. You get an amount of {E} (energy counters) equal to the number of nonbasic lands that player controls.
Whenever The Motherlode attacks, you may pay {E}{E}{E}{E}. When you do, destroy target nonbasic land defending player controls, and creatures that player controls without flying can't block this turn.

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.

Eddytrail Hawk

Flying
When Eddytrail Hawk enters the battlefield, you get {E}{E} (two energy counters).
Whenever Eddytrail Hawk attacks, you may pay {E}. If you do, another target attacking creature gains flying until end of turn.

Satya, Aetherflux Genius

Menace, haste
Whenever Satya, Aetherflux Genius attacks, create a tapped and attacking token that's a copy of up to one other target nontoken creature you control. You get {E}{E} (two energy counters). At the beginning of the next end step, sacrifice that token unless you pay an amount of {E} equal to its mana value.

Aether Theorist

When Aether Theorist enters the battlefield, you get {E}{E}{E} (three energy counters).
{T}, Pay {E}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Aethertorch Renegade

When Aethertorch Renegade enters the battlefield, you get {E}{E}{E}{E} (four energy counters).
{T}, Pay {E}{E}: Aethertorch Renegade deals 1 damage to target creature.
{T}, Pay eight {E}: Aethertorch Renegade deals 6 damage to target player or planeswalker.

Conduit Goblin

When Conduit Goblin enters the battlefield, you get {E}{E} (two energy counters).
At the beginning of combat on your turn, you may pay {E}. If you do, another target creature you control gets +1/+0 and gains haste until end of turn.

Behemoth of Vault 0

Trample
When Behemoth of Vault 0 enters the battlefield, you get {E}{E}{E}{E} (four energy counters).
When Behemoth of Vault 0 dies, you may pay an amount of {E} equal to target nonland permanent's mana value. When you do, destroy that permanent.

Metastatic Evangel

Whenever another nontoken creature 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.)

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.

Aether Refinery

If you would get one or more {E}, you get twice that many {E} instead.
{T}: You get {E}, then you may pay one or more {E}. If you do, create an X/X black Aetherborn creature token, where X is the amount of {E} paid this way.

Galvanic Discharge

Choose target creature or planeswalker. You get {E}{E}{E} (three energy counters), then you may pay any amount of {E}. Galvanic Discharge deals that much damage to that permanent.

Grateful Apparition

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

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.

Amped Raptor

First strike
When Amped Raptor enters the battlefield, you get {E}{E} (two energy counters). Then if you cast it from your hand, exile cards from the top of your library until you exile a nonland card. You may cast that card by paying an amount of {E} equal to its mana value rather than paying its mana cost.

Gonti's Aether Heart

Whenever Gonti's Aether Heart or another artifact enters the battlefield under your control, you get {E}{E} (two energy counters).
Pay eight {E}, Exile Gonti's Aether Heart: Take an extra turn after this one.

Whirler Virtuoso

When Whirler Virtuoso enters the battlefield, you get {E}{E}{E} (three energy counters).
Pay {E}{E}{E}: Create a 1/1 colorless Thopter artifact creature token with flying.

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Lightning Runner

Double strike, haste
Whenever Lightning Runner attacks, you get {E}{E} (two energy counters), then you may pay eight {E}. If you pay, untap all creatures you control, and after this phase, there is an additional combat phase.

Janjeet Sentry

When Janjeet Sentry enters the battlefield, you get {E}{E} (two energy counters).
{T}, Pay {E}{E}: You may tap or untap target artifact or creature.

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.

Scurry of Gremlins

When Scurry of Gremlins enters the battlefield, create two 1/1 red Gremlin creature tokens. Then you get an amount of {E} (energy counters) equal to the number of creatures you control.
Pay {E}{E}{E}{E}: Creatures you control get +1/+0 and gain haste until end of turn.

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land enters the battlefield under your control, you may draw a card.