msem-instigator

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.)

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.

Exile target permanent, then return that card to the battlefield under its owner's control.

Whenever a nontoken creature you control dies, you may put a +1/+1 counter on target creature. If you do, that creature's controller loses 1 life.

Double strike
Whenever Eldan Jackson deals combat damage, return target permanent card with mana value 3 or less from your graveyard to the battlefield.

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.

When Elder Prophesier enters, look at the top five cards of your library. You may reveal a Curse card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Flying
When Elder Roc enters, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)

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

Whenever Chian becomes the target of a spell or ability you control, create a 2/2 blue Drake creature token with flying. This ability triggers 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}

At the beginning of each combat, you may have Elderin, Crystalline Crusader become a copy of another target creature you control with mana value 3 or less until end of turn, except its name is still Elderin, Crystalline Crusader, it's still 3/3, still legendary, and it's an artifact in addition to its other types.
{W}{U}{B}{R}{G}: Elderin gets +3/+3 until end of turn.

When Elderthrone Castellan enters, you may search your library for a Plains card, reveal it, put it into your hand, then shuffle.

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

Whenever one or more creatures you control deal combat damage to a player or planeswalker, create a Clue token.
{G}{U}, Sacrifice a Clue: Put a +1/+1 counter on target creature. Proliferate.

{0}: Until end of turn, Eldritch Egg becomes a copy of target permanent card in a graveyard with mana value 6 or less except it's an artifact. Activate only once each turn. (It has no other card types.)

You may cast this spell as though it had flash if you control a Horror creature.
Destroy all non-Horror creatures.

You may reveal an Avatar or planeswalker card you own from outside the game and put it into your hand.

Primal {U} (During your turn, you may cast this spell for {U} instead of playing a land.)
Counter target spell.

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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.

Put a +1/+1 counter on target creature you control. Untap that creature.

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.