msem-instigator

Flying, haste
Whenever Epoch Warden attacks, you may aetherize another target attacking creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever you cast an instant or sorcery spell, create a 1/1 red Alien creature token with “This creature can't block.”
{2}{R}, Sacrifice two Aliens: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Artifacts you control have “{T}: Add one mana of any color.”
{2}{R}{G}: Create a 3/2 green Crocodile creature token with trample. It gains haste until end of turn.

Whenever another creature you control enters, put your choice of a vigilance, reach, or trample counter on this creature.
{T}, Remove a counter from this creature: Add one mana of any color. If that mana is spent on a creature spell, you may have it enter the battlefield with an additional counter of that kind on it.

When Esiara, Skycaster's Infiltrator enters, exile target spell with mana value 4 or less.
{1}{U}{U}, Discard two cards: Exile Esiara, then return it to the battlefield under your control.
{2}{U}{U}, {T}, Exile Esiara: Until end of turn, you may play cards you don't own from exile.

Flying, vigilance
Embattled creatures you control have ward {1}. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Whenever one or more creatures you control deal combat damage to a player, put a +1/+1 counter on one of those creatures.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Flying
Whenever Eta, Experimental Doctor attacks, you may exile target card from a graveyard. If a creature card was exiled this way, put a +1/+1 counter on Eta and you gain 2 life.

Lifelink
Whenever you draw your second card each turn, put a +1/+1 counter on Ethereal Runner.

Flying
When Ethereal Savior enters, you may return target creature card with mana value 2 or less from your graveyard to the battlefield.

Flying
Deploy 2 (As this enters, you may tap any number of other creatures you control with total power 2 or more.)
When Ethereal Shepherd enters deployed, exile target creature. That creature's controller creates a 1/1 white Spirit creature token with flying.

Whenever you draw your second card each turn, put a +1/+1 counter on Ethereal Sneak.

Artifact spells you cast cost {1} less to cast.

Stampede — Whenever Etlan High Priest and a creature with greater power attack, Etlan High Priest gets +1/+1 until end of turn. Then you gain 1 life and scry 1.

When Evanescier Greypelt enters, it fights target creature.
Mirage {3}{G} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

{1}, Sacrifice a creature: Put a +1/+1 counter on Ever-Wandering Pilgrim.
Surpass {5}{B} ({5}{B}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Flying
Whenever Everember Phoenix deals combat damage to a player or planeswalker, you may put target exiled card you own or card in your graveyard that shares a name with it into your hand.
Revive {1}{R}{R} ({1}{R}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Flying, vigilance

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you gain life, you may pay {W}. If you do, transform Evigian Noble.

First strike
When Excavator of the Beyond enters, rediscover an artifact card. (Look at the top card of your library. You may reveal it and put it into your hand if it's an artifact card. Otherwise, put it back or into your graveyard.)

First strike, vigilance, lifelink

Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)
When Exiled Warband dies, draw a card.

Other Elves you control get +1/+1.
Whenever another Scout you control deals combat damage to a player, you may reveal the top card of your library. If it's a land card, put it onto the battlefield tapped.

When Expedition Outfitter enters, create a 1/1 colorless Servo artifact creature token.
At the beginning of each end step, if an artifact was put into your graveyard from the battlefield this turn, Expedition Outfitter deals 1 damage to each opponent.

When Expensive Tutor enters, tap target land. It doesn't untap during its controller's next untap step.