msem-instigator

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.

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.)

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.

{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.

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.

Exile up to three instant or sorcery cards from your graveyard. You may cast a copy of each card exiled this way without paying its mana cost.

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.

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.

[+1]: Create a tapped colorless Bullet artifact token with “{T}, Sacrifice this artifact: It deals 1 damage to any target.”
[–1]: Exile target creature or planeswalker that was dealt damage this turn.
[–7]: You get an emblem with “At the beginning of each end step, you may draw X cards, where X is the amount of life your opponents lost this turn.”

At the beginning of combat on your turn, creatures you control gain your choice of trample, menace, haste, or +1/+0 until end of turn.