Aether Hub

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

Rogue Refiner

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

Game Trail

As Game Trail enters, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters tapped.
{T}: Add {R} or {G}.

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Serra's Emissary

Flying
As Serra's Emissary enters, choose a card type.
You and creatures you control have protection from the chosen card type.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.

Aetherwind Basker

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

Harnessed Lightning

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.

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.

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.

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.

Aethertorch Renegade

When Aethertorch Renegade enters, 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.

Whirler Virtuoso

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

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.