Electrostatic Pummeler

When Electrostatic Pummeler enters, 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.

Nature's Way

Target creature you control gains vigilance and trample until end of turn. It deals damage equal to its power to target creature you don't control.

Servant of the Conduit

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

Larger Than Life

Target creature gets +4/+4 and gains trample until end of turn.

Sage of Shaila's Claim

When Sage of Shaila's Claim enters, you get {E}{E}{E} (three energy counters).

Die Young

Choose target creature. You get {E}{E} (two energy counters), then you may pay any amount of {E}. The creature gets -1/-1 until end of turn for each {E} paid this way.

Glint-Sleeve Siphoner

Menace
Whenever Glint-Sleeve Siphoner enters 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.

Aethersphere Harvester

Flying
When Aethersphere Harvester enters, 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.)

Aether Hub

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

Forest

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Bristling Hydra

When Bristling Hydra enters, 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.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Live Fast

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

Greenbelt Rampager

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

Swamp

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.

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).

Highspire Infusion

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

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.