First strike

When Aether Chaser enters the battlefield, you get {E}{E} (two energy counters).

Whenever Aether Chaser attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

When Aether Hub enters the battlefield, you get {E} (an energy counter).

{T}: Add {C}.

{T}, Pay {E}: Add one mana of any color.

Flash (You may cast this spell any time you could cast an instant.)

Enchant creature or Vehicle

When Aether Meltdown enters the battlefield, you get {E}{E} (two energy counters).

Enchanted creature gets -4/-0.

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.

Flying

When Aether Swooper enters the battlefield, you get {E}{E} (two energy counters).

Whenever Aether Swooper attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

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.)

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.

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.

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.

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.

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

Blooming Marsh enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {B} or {G}.

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {G} or {U}.

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.

({T}: Add {B} or {R}.)

Canyon Slough enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

Clifftop Retreat enters the battlefield tapped unless you control a Mountain or a Plains.

{T}: Add {R} or {W}.

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.

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.

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.

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.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.

{T}: Add {U} or {B}.

Whenever you cast an instant or sorcery spell, you get {E}{E} (two energy counters).

{T}, Pay {E}{E}{E}{E}{E}: Dynavolt Tower deals 3 damage to any target.

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.

Flying, trample

Whenever Empyreal Voyager deals combat damage to a player, you get that many {E} (energy counters).

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

When Felidar Guardian enters the battlefield, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

({T}: Add {U} or {B}.)

Fetid Pools enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

({T}: Add {G}.)

({T}: Add {G}.)

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.

{T}: Add {W} or {U}.

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

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.

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.

When Greenbelt Rampager enters the battlefield, pay {E}{E} (two energy counters). If you can't, return Greenbelt Rampager to its owner's hand and you get {E}.

Choose target creature. You get {E}{E}{E} (three energy counters), then you may pay any amount of {E}. Harnessed Lightning deals that much damage to that creature.

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.

{T}: Add {G} or {U}.

Inspiring Vantage enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {R} or {W}.

({T}: Add {U}.)

({T}: Add {U}.)

Flying

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells that you cast.

Haste

When Lathnu Hellion enters the battlefield, you get {E}{E} (two energy counters).

At the beginning of your end step, sacrifice Lathnu Hellion unless you pay {E}{E}.

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.

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.

When Minister of Inquiries enters the battlefield, you get {E}{E} (two energy counters).

{T}, Pay {E}: Target player mills three cards.

({T}: Add {R}.)

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.

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

({T}: Add {W}.)

{T}: Add {C}.

{T}, Pay 1 life: Add {R}.

{2}{R}{R}, {T}, Sacrifice a Desert: Ramunap Ruins deals 2 damage to each opponent.

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

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.

{T}: Add {R} or {G}.

+1: Scry 1. Saheeli Rai deals 1 damage to each opponent.

-2: Create a token that's a copy of target artifact or creature you control, except it's an artifact in addition to its other types. That token gains haste. Exile it at the beginning of the next end step.

-7: Search your library for up to three artifact cards with different names, put them onto the battlefield, then shuffle.

({T}: Add {G} or {W}.)

Scattered Groves enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

When Servant of the Conduit enters the battlefield, you get {E}{E} (two energy counters).

{T}, Pay {E}: Add one mana of any color.

({T}: Add {R} or {G}.)

Sheltered Thicket enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {U} or {R}.

({T}: Add {B}.)

Trample

Whenever you get one or more {E} (energy counters), Territorial Gorger gets +2/+2 until end of turn.

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.

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.