msem-instigator

Counter target spell unless its controller pays its mana cost. (For example, if a spell costs {1}{U}{U}, its controller must pay {1}{U}{U}.)

When Prodigious Telemancer enters, you may draw a card, then discard a card.
Whenever you cast an instant or sorcery spell, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Flash
Flying
When Powder Scatterer enters, exile target noncreature spell. Its controller draws a card.

Create a token that's a copy of target permanent you control, except it isn't legendary. Then put Picture Perfect on the bottom of its owner's library if you cast it from exile.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

[+1]: Copy the next spell you cast this turn. You may choose new targets for the copy.
[–3]: Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.
[–8]: You get an emblem with “You may cast spells without paying their mana costs.”

Search your library for up to two cards with different names and reveal them. Target opponent chooses one of those cards. Put the chosen card into your graveyard and the rest into your hand. Then shuffle.

Instant and sorcery spells you cast cost {1} less to cast.
{U}, {T}, Exile three instant and/or sorcery cards from your graveyard: Draw a card.

Counter target spell. If a permanent spell is countered this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying
When Lord Rokai becomes the target of a spell, sacrifice it.
Whenever you cast an instant or sorcery spell, you may pay {2}{U}. If you do, return Lord Rokai from your graveyard to the battlefield.

Take an extra turn after this one. Exile Look to the Future.
Civilized — If you control an artifact, a creature, and an enchantment, until the end of your next turn, you may look at the top card of your library any time and you may play the top card of your library.

[+1]: Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.
[–2]: Return target card from your graveyard to the battlefield face down.
[–6]: Turn any number of face-up nonland permanents of your choice face down.

When Gitaxian Reprocessor enters, if you cast it, choose one —
• Create a token that's a copy of another target creature, except it's an artifact and isn't a creature.
• Create a token that's a copy of target noncreature artifact, except it's a 2/2 creature in addition to its other types.

Choose X. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target nonland permanent to its owner's hand.
• Target player draws a card.

Flash
When Emissary of Dark Tides enters, you may return target noncreature spell or tapped creature to its owner's hand.

If you would draw one or more cards, instead you may draw that many cards plus one, then discard a card.
As long as ten or more cards are in your graveyard, noncreature spells you cast cost {1} less to cast.

Flash
When Duplicated Dismantler enters, if you cast another spell this turn, return target spell to its owner's hand.

[+1]: Draw two cards.
[–1]: Until your next turn, Director Amitai Eliahu gains “Other nonland permanents lose all abilities.”
[–3]: You may discard a card. If you do, you may cast a spell that shares a color with that card without paying its mana cost.
[–9]: Until end of turn, play with your library revealed. You may cast spells from your library this turn.

You may have Blurry Counterpart enter as a copy of any creature on the battlefield.
Mirage {1}{U} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

You may put a creature or Revelation card from your hand onto the battlefield. Exile that permanent if it would leave the battlefield. If it's a Revelation, it enters as a Horror creature.
Coalesce {7}{U}{U} (You may cast this from your graveyard for {7}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Flash
When Aethermancer's Familiar enters, at the beginning of the next end step, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying, lifelink
At the beginning of each end step, if you gained 3 or more life this turn, choose one —
• Put a +1/+1 counter on Waxing Angel.
• Exile target artifact or enchantment.

Motivate 1 (When this creature enters, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)
{2}{W}{W}: Exile Valtrian Cavalier, then return it to the battlefield under your control.

Flash
Flying
When Turela, Defiant Angel enters, exile all other creatures you control. Return them to the battlefield under their owner's control at the beginning of the next end step.

(As this Discovery enters and after your draw step, add a progress counter. Stop after you've discovered.)
I, II — Look at the top five cards of your library. Put up to one creature card with mana value 2 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Discovery — At the beginning of combat on your turn, tap target creature an opponent controls.

Choose one —
• Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.
• Until end of turn, if a creature would enter and it wasn't cast, exile it instead.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)