msem-instigator

Haste
When Efreetspeaker dies, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

{1}, {T}, Sacrifice a creature: Search your library for a creature card with mana value 1, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Your opponents can't gain life.
Whenever you cast a noncreature spell, put a +1/+1 counter on Eidolon of the Arena.

{1}, {T}: Draw a card, then exile a card from your hand face down.
You may look at cards exiled with Ekebram's Archive.
{4}, {T}, Sacrifice Ekebram's Archive: Return all cards exiled with Ekebram's Archive to their owner's hand.

When El, Humble Apprentice enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)

{T}: Add {C}.
{2}, {T}: Add {C} for each Desert you control.

Elaborate Firecannon doesn't untap during your untap step.
{4}, {T}: Elaborate Firecannon deals 2 damage to any target.
At the beginning of your upkeep, you may discard a card. If you do, untap Elaborate Firecannon.

Whenever Hatsuo attacks, if you control three or more attacking creatures, attacking creatures you control gain first strike until end of turn.
Inspired — Whenever Hatsuo becomes untapped, create a 1/1 white Warrior creature token. It gains haste and attacks this turn if able.

{3}{G}: Elder Rootwallas gets +4/+2 until end of turn. Activate only once each turn.

At the beginning of your upkeep, look at the top four cards of your library. You may reveal a storied card from among them and put it into your hand. Put the rest on the bottom of your library in any order. (Enchantment and legendary cards are storied.)

Equipped creature gets +2/+0.
Whenever a creature blocks equipped creature, you may sacrifice Elderbane Rifle. If you do, destroy that creature.
Equip {2}

{T}: Add one mana of any color.
{T}, Sacrifice Elderthrone Shard: Draw a card.

[progress 2+]
[progress 5+]
Whenever a creature enters, each opponent loses 1 life.

Electrical Eradication deals 3 damage to each nonlegendary creature. Then if you controlled a red legendary creature or planeswalker as you cast this spell, it deals 3 damage to each nonlegendary creature and each opponent.

Electrokinetic's Bolt deals 3 damage to target creature or planeswalker.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Electrokinetic's Bolt deals 3 damage to that permanent's controller.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, you may have Elegant Fireslinger deal 1 damage to target creature.

Elegant Strike deals 2 damage to target tapped creature. Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Elemental Envelopment enters with X +1/+1 counters on it.
When Elemental Envelopment enters, if you controlled a green legendary creature or planeswalker as you cast it, search your library for any number of Elemental creature cards with total mana value X or less, where X is Elemental Envelopment's power, put them onto the battlefield, then shuffle.

{T}: Add {C} and one mana of any color.

When Elemental Loremaster enters, return an instant or sorcery card at random from your graveyard to your hand.

Target creature gets +X/+X until end of turn, where X is 3 plus the number of cards named Elemental Power in your graveyard.

Flash
Creatures you control that have entered this turn get +1/+1 and have haste and first strike.

Reach
Whenever Elemental of Vengeance is dealt damage, it deals damage equal to its power to any target.

Equipped creature gets +1/+1 and has prowess.
Equip {2}

Create three tapped colorless Powercell artifact tokens with “{T}: Add {C}.” Then untap all artifacts you control. At the beginning of the next end step, sacrifice three artifacts.