msem-instigator

Whenever Ekebram the Scholar becomes untapped, draw a card.
Whenever you draw your third card each turn, you may transform Ekebram.

Indestructible
Whenever a creature you control becomes untapped, draw a card.

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.

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.

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.)

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.

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.)

[+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.

{1}{R}, {T}, Sacrifice an artifact: Elise, Maktali Prodigy deals 2 damage to any target.
{1}{U}, {T}, Sacrifice an artifact: Return target nonland permanent to its owner's hand.
{3}{U}{R}, {T}, Sacrifice three artifacts: Discard your hand, then draw seven cards.

Flash
Prowess
When Ella enters, create two 1/1 blue Wizard creature tokens with prowess.
Whenever you cast a noncreature spell, you may sacrifice a creature. If you do, copy that spell. You may choose new targets for the copy.

At the beginning of your upkeep, you may search your library for a permanent card with mana value 1 or less, put it onto the battlefield, then shuffle.

During each of your turns, you may cast a card with a cycling ability from your graveyard by discarding a card in addition to paying its other costs. If that spell would be put into your graveyard, exile it instead.
Cycling {2} ({2}, Discard this card: Draw a card.)

Elrayin, the Manaroot enters tapped.
Whenever you tap another land for mana, put a creation counter on Elrayin.
{T}, Remove ten creation counters from Elrayin and sacrifice it: Untap all lands target player controls.

[+1]: Create a 1/1 white Warrior creature token.
[–1]: Another target permanent you control gains indestructible until your next turn.
[–8]: You get an emblem with “Creatures you control get +2/+2.” and “Prevent all damage that would be dealt to attacking creatures you control.”

Whenever you cast an instant or sorcery spell, exile cards from the top of your library until you exile an instant or sorcery card. You may cast that card until you exile another card with this ability.

(Transform this if it's not attached to a creature. Pay {3}{G} as a sorcery to unattach it.)
Enchant creature you control
Elven Mount's rider gets +3/+3 and has trample.

At the beginning of combat on your turn, look at the top card of your library. You may reveal it. If you do, target creature gets +X/+X until end of turn, where X is the revealed card's mana value.

When Ema, the Traveler enters, reveal the top five cards of your library. Put any number of legendary cards revealed this way into your hand and the rest on the bottom of your library in any order.
{2}{B}: Another target legendary permanent gains indestructible until end of turn.

Enchant artifact or creature
When Embed enters, tap enchanted permanent.
Enchanted permanent doesn't untap during its controller's untap step.