msem-instigator

First strike
When Engulfing Incubus enters, you may submerge target nontoken creature an opponent controls. When Engulfing Incubus is no longer on the battlefield, turn that card face up. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

When Enhance Armor enters, return an enchantment card from your graveyard to your hand.
Whenever you cast an enchantment spell, put a +1/+1 counter on a creature you control.

When Enigma Mystic enters, mill three cards.
Enigma Mystic gets +2/+0 as long as there's a Shaman card in your graveyard.
{T}: Add one mana of any color. Activate only if you control another Shaman.

Whenever a creature attacks you or a planeswalker you control, upgrade Enigmatic Protector. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying
• Prowess

Converge — Each creature gets -X/-X until end of turn, where X is the number of colors of mana spent to cast Enjoy the Silence.

First strike
When Enlistment Officer enters, reveal the top four cards of your library. Put all Soldier cards revealed this way into your hand and the rest on the bottom of your library in any order.

Deathtouch
Enopraxia gets +3/+3 as long as there are three or more creature cards in your graveyard.
At the beginning of your end step, if a creature card was put into your graveyard from anywhere this turn, draw a card.

Trample
Whenever a creature you control with trample is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Flying
Whenever Entali Aeromancer attacks, Elementals you control gain flying until end of turn.

Landfall — Whenever a land you control enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Whenever you make first contact, exile the top card of your library. You gain life equal to its mana value. You may play that card until the end of your next turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Entelan Duelist.
{2}{U}{R}, Remove two +1/+1 counters from Entelan Duelist: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Whenever a Role is attached to a creature you control or you cast a spell that targets a creature you control, put a +1/+1 counter on Enthusiastic Admirer.

Whenever another creature dies, upgrade Entitled Griefer. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Deathtouch
• Lifelink

Return target card from your graveyard to your hand. Distribute X +1/+1 counters among any number of creatures you control, where X is that card's mana value. Exile Entropic Harvest.

{T}: Envious Nereid deals 1 damage to target creature and 1 damage to that creature's controller.

{T}: Add {C}.
{4}, {T}, Sacrifice Eon Campfire: Destroy target artifact or nonbasic land.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Eos Beseecher encourages a creature, look at the top card of your library. If it's a creature card with power 2 or less, you may reveal it and put it into your hand.

Enchant creature
Enchanted creature has double strike.
Mirage {1}{W} (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.)

Scry X, where X is target creature's power.
Fabled {5}{U}{U} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

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.)

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Until your next turn, target creature an opponent controls gets -1/-0.
[Lore III] Scry 2, then draw a card.

When Equinox Sprite enters, return target card from your graveyard to your hand.

Kicker {W} (You may pay an additional {W} as you cast this spell.)
Target player sacrifices an attacking creature. If this spell was kicked, you gain life equal to the sacrificed creature's power.

Whenever you cast an instant or sorcery spell, upgrade Error Exploiter. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying
• Hexproof