msem-instigator

When Shapur, the Fifth Shah enters, exile target instant or sorcery card from your graveyard. Until end of turn, you may cast that card. If that spell would be put into a graveyard, exile it instead.
Monument {4}{R} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

When Shara, Prime Geneticist enters, if X isn't 0, create two X/X green Mutant creature tokens.
[+1]: Surveil 2. At the beginning of your next end step, untap up to one permanent.
[–2]: Conjure a card named Test Run into your hand. (It's a sorcery that costs {X}{G} with “Create an X/X green Mutant creature token. Draw a card.”)
[–7]: Search your library for a card and put it into your hand. Repeat this process once for each token you control. Then shuffle.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

When you cast an instant or sorcery spell, you may sacrifice Shard Flower. If you do, copy that spell. You may choose new targets for the copy.

Equipped creature gets +1/+1 and has distorted. (It can be blocked by tapped creatures but not untapped creatures.)
Equip {1}

When Shardsong Seedling enters, conjure two cards named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Discard a land card: Draw a card. Shardstorm Elemental gets +1/+0 and gains flying until end of turn. Activate only once each turn.

If one or more +1/+1 counters would be put on a creature you control, put that many +1/+1 counters on each creature you control instead.

Return up to two target cards from your graveyard to your hand. Put Shared Reminiscence on the bottom of its owner's library.

{T}: Each player draws a card.

Each creature you control has base power and toughness X/Y, where X is the greatest base power among creatures you control and Y the greatest base toughness among creatures you control.

When Shark Slayer enters, you may destroy target creature with mana value less than or equal to the number of artifacts you control.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Spell you cast cost {1} less to cast as long as it's not your turn.

Flash
Unveil {3}{B}{G} ({3}{B}{G}: Transform this. Unveil only as a sorcery.)

Flying
When Sharp-Eyed Wingmate enters, you may return target creature to its owner's hand.

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)

Creatures you control get +1/+0.
Ferocious — At the beginning of combat on your turn, creatures you control with power 4 or greater gain trample until end of turn.

Lifelink
Each other artifact creature you control enters with an additional +1/+1 counter on it.

Flash
Flying
When Sharuum, Archmagocrat enters, return to the battlefield all nonlegendary artifact cards in your graveyard that were put there from the battlefield this turn.

Destroy target artifact.

Destroy target creature if it has mana value 4 or greater. If Shatter Facade was cast from exile, destroy that creature if it has mana value 3 or less instead.
Orchestrate {B} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Return each nonland permanent you don't control to its owner's hand.
Coalesce {6}{U}{U}{U} (You may cast this from your graveyard for {6}{U}{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.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Destroy target noncreature permanent.
Memento {5}{G}{G} (You may cast this from your graveyard for {5}{G}{G}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

Create a token that's a copy of target creature.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Whenever a player casts a creature spell, they sacrifice a creature.
Revive—{3}{B}{G}, Sacrifice a creature. ({3}{B}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)