msem-instigator

As Duke Gerard Hoff enters, an opponent gains control of it.
Duke Gerard Hoff can't attack its owner or planeswalkers that player controls.
Creatures your opponents control get +2/+1.

[+2]: You may discard a card. If you do, draw two cards.
[–3]: Return target creature card from your graveyard to the battlefield. It gains haste. Return it to your hand at the beginning of the next end step.
[–7]: Discard your hand, then draw seven cards. You may put an Edarna planeswalker card from your hand or graveyard onto the battlefield.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead, except the additional tokens are named Ingenious Idea.
At the beginning of your end step, exile each token you control named Ingenious Idea.

If a spell or ability an opponent controls causes you to discard Edgar, put it onto the battlefield instead of putting it into your graveyard.
Unveil {4}{G}{W} ({4}{G}{W}: Transform this. Unveil only as a sorcery.)

{W}{B}, {T}: Exile target nonland permanent until Ediam, the Inside Man leaves the battlefield. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.

Whenever you cast an artifact or enchantment spell, scry 1, then create a 1/1 white Merfolk creature token.
Whenever you cast a Merfolk spell, look at the top card of your library. If it's an artifact or enchantment card, you may reveal it and put it into your hand.

[+1]: Untap up to one target creature.
[0]: Edith Waunt becomes a legendary green Human creature with “This creature's power and toughness are each equal to the number of loyalty counters on it” and “Whenever this creature deals damage, put a loyalty counter on it” until your next turn.

Ward—Pay 3 life and discard a card.
Once each turn, when another creature leaves the battlefield, you may have target creature become a copy of that creature until end of turn.

Vigilance
Each nontoken creature you control gets +1/+1 for each other creature on the battlefield with the same name as it.

Whenever another creature you control enters, target instant or sorcery card in your graveyard with mana value less than or equal to that creature's power gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

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

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.)

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 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.

[+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.

[+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.

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.