msem-instigator

When Entelan Savant enters, scry 2.

Destroy target creature.

Up to one target attacking creature gets +3/+3 and gains trample until end of turn.
Harmonize. (Trigger up to one harmony of a permanent you control.)

When Enter the Wormhole enters or leaves the battlefield, draw a card.
Whenever you cast a noncreature spell, target player mills a card.

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

Choose one —
• Prevent all damage that would be dealt by creatures this turn.
• Harmonize twice. (Trigger up to one harmony of a permanent you control.)

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.

Equipped creature gets +1/+0 and has poisonous 1. (Whenever it deals combat damage to a player, that player gets a poison counter.)
Equip {1}

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

When Envoy of Growth enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Vigilance
When Envoy of Karametra enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

{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.

Flying
When Ephara's Watcher enters, scry 2.

Flying, lifelink

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.)

Epic Boss Fight deals 5 damage to target creature or planeswalker.
Menagerie — If there are five or more creature types among creatures you control, Epic Boss Fight deals 3 damage to that permanent's controller.

Target creature you control gets +1/+2 until end of turn. It fights target creature you don't control.

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.

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.

Enchant creature you control
When Erebos's Benefaction enters, scry 2.
Enchanted creature gets +2/+2 and has menace.