Lightning Runner

Double strike, haste
Whenever this creature 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.

The Motherlode, Excavator

When The Motherlode enters, 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.

Shielded Aether Thief

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

Training Center

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Glimmer of Genius

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

Scrapper Champion

Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Arcane Signet

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

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Era of Innovation

Whenever an artifact or Artificer you control enters, you may pay {1}. If you do, you get {E}{E} (two energy counters).
Pay six {E}, Sacrifice this enchantment: Draw three cards.

Plasma Caster

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you get {E}{E} (two energy counters).
Pay {E}{E}: Choose target creature that's blocking equipped creature. Flip a coin. If you win the flip, exile the chosen creature. Otherwise, this Equipment deals 1 damage to it.
Equip {2}

Amped Raptor

First strike
When this creature enters, 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.

Aurora Shifter

Whenever this creature deals combat damage to a player, you get that many {E}.
At the beginning of combat on your turn, you may pay {E}{E}. When you do, this creature becomes a copy of another target creature you control, except it has this ability and "Whenever this creature deals combat damage to a player, you get that many {E}."

Decoction Module

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

Izzet Boilerworks

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Synth Eradicator

Haste
Whenever this creature attacks, exile the top card of your library. You may get {E}{E} (two energy counters). If you don't, you may play that card this turn.
{T}, Pay {E}{E}{E}: This creature deals 3 damage to any target.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Reiterating Bolt

Replicate—Pay {E}{E}{E}. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Reiterating Bolt deals 3 damage to target creature or planeswalker.

Solar Transformer

This artifact enters tapped.
When this artifact enters, you get {E}{E}{E} (three energy counters).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice this artifact: Create a 10/10 colorless Eldrazi creature token.

Robobrain War Mind

Robobrain War Mind's power is equal to the number of cards in your hand.
When this creature enters, you get an amount of {E} (energy counters) equal to the number of artifact creatures you control.
Whenever this creature attacks, you may pay {E}{E}{E}. If you do, draw a card.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Tune the Narrative

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

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.

Overclocked Electromancer

At the beginning of combat on your turn, you may pay {E}{E}{E}. If you do, put a +1/+1 counter on this creature.
Whenever this creature attacks, double its power until end of turn.
Whenever this creature deals combat damage to a creature, if that creature was dealt excess damage this turn, you get X {E}, where X is that excess damage.

Path of Ancestry

This land enters 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.)

Whirler Virtuoso

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

Conversion Apparatus

{T}: Add {C}.
{3}, {T}: You get {E}{E}{E} (three energy counters).
{T}, Pay {E}{E}{E}: Add three mana in any combination of colors.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Mountain

Deadlock Trap

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

Aethersquall Ancient

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

Stone Idol Generator

Whenever a creature you control attacks, you get {E} (an energy counter).
{T}, Pay six {E}: Create a 6/12 colorless Construct artifact creature token with trample. Activate only as a sorcery.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

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}: This Vehicle becomes an artifact creature until end of turn.
Crew 4

Assaultron Dominator

When this creature enters, 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.

Aethertorch Renegade

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

Behemoth of Vault 0

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

Crackling Falls

This land enters 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

Saheeli, the Sun's Brilliance

{U}{R}, {T}: Create a token that's a copy of another target creature or artifact you control, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

Aether Refinery

If you would get one or more {E} (energy counters), 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.

Island

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Unstable Amulet

When this artifact enters, you get {E}{E} (two energy counters).
Whenever you cast a spell from anywhere other than your hand, this artifact deals 1 damage to each opponent.
{T}, Pay {E}{E}: Exile the top card of your library. You may play it until you exile another card with this artifact.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Ingot Chewer

When this creature enters, destroy target artifact.
Evoke {R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Volatile Stormdrake

Flying, hexproof from activated and triggered abilities
When this creature enters, exchange control of this creature 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.

Izzet Signet

Stormcarved Coast

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Aether Hub

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

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.

HELIOS One

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

Vault 112: Sadistic Simulation

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap up to one target creature and put a stun counter on it. You get {E}{E} (two energy counters).
III — Pay any amount of {E}. If you paid one or more {E} this way, shuffle your library, then exile that many cards from the top. You may play one of those cards without paying its mana cost.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Aetherflux Conduit

Whenever you cast a spell, you get an amount of {E} (energy counters) equal to the amount of mana spent to cast that spell.
{T}, Pay fifty {E}: Draw seven cards. You may cast any number of spells from your hand without paying their mana costs.

Gonti's Aether Heart

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

Aethertide Whale

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

Phyrexian Ironworks

Whenever you attack, you get {E} (an energy counter).
{T}, Pay {E}{E}{E}: Create a 3/3 colorless Phyrexian Golem artifact creature token. Activate only as a sorcery.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.

Janjeet Sentry

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

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.

All Will Be One

Whenever you put one or more counters on a permanent or player, this enchantment deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Aetherworks Marvel

Whenever a permanent you control is put into a graveyard, you get {E} (an energy counter).
{T}, Pay six {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.

T-45 Power Armor

When this Equipment enters, you get {E}{E} (two energy counters).
Equipped creature gets +3/+3 and doesn't untap during its controller's untap step.
At the beginning of your upkeep, you may pay {E}. If you do, untap equipped creature, then put your choice of a menace, trample, or lifelink counter on it.
Equip {3}

Filigree Racer

When this Vehicle enters, you get {E}{E}{E}{E} (four energy counters).
Whenever this Vehicle attacks, you may pay {E}{E}. When you do, target instant or sorcery card in your graveyard gains jump-start until end of turn. (You may cast that card from your graveyard by discarding a card in addition to paying its other costs. Then exile it.)
Crew 1

Command Tower

Wheel of Potential

You get {E}{E}{E} (three energy counters), then you may pay any amount of {E}.
Each player may exile their hand and draw a number of cards equal to the amount of {E} paid this way. If seven or more {E} was paid this way, you may play cards you own exiled this way until the end of your next turn.

Territorial Aetherkite

Flying, haste
When this creature enters, you get {E}{E} (two energy counters). Then you may pay one or more {E}. When you do, this creature deals that much damage to each other creature.

Aether Revolt

Revolt — As long as a permanent left the battlefield under your control this turn, if a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.
Whenever you get one or more {E}, this enchantment deals that much damage to any target.

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.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Roil Cartographer

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

Blaster Hulk

This spell costs {1} less to cast for each {E} (energy counter) you've paid or lost this turn.
Haste
Whenever this creature attacks, you get {E}{E}, then you may pay eight {E}. When you do, this creature deals 8 damage divided as you choose among up to eight targets.

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Electrosiphon

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