msem-instigator

Creatures can't attack you unless their controller pays {2} for each of those creatures.
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.)

Target creature you control deals damage equal to its power to another target creature. You gain 3 life.

Predatory Abomination has deathtouch and lifelink as long as you control another Horror.

Choose a creature. When it dies this turn, distribute two +1/+1 counters among any number of creatures you control.

Flash
When Predatory Psion enters, switch target creature's power and toughness until end of turn.

Enchant creature
You choose whether enchanted creature attacks each combat rather than its controller (after its controller chooses which of their other creatures attack. That player still chooses the player or planeswalker it attacks.)

Nontoken creatures get -2/-2 until end of turn.
Fuse (You may cast one or both halves of this card from your hand.)

If one or more +1/+1 counters or quest counters would be put on a permanent you control, that many plus one of those counters are put on it instead.

Scry 3.
Catalyze. (The next spell you cast this turn costs {1} less to cast.)

Creatures you control get +0/+2 until end of turn. Untap those creatures.

Put a +1/+1 counter on target creature.
Draw a card.

Target creature you control gains double strike until end of turn. That creature also gains trample until end of turn if you control a creature with power 4 or greater.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a creature you control enters, add a quest counter.
Create a Treasure token.
Creatures you control get +2/+2 and gain trample and haste until end of turn.
​

Creatures you control gain deathtouch until end of turn and must be blocked this turn if able.

When Presence of the Unknown enters, you may sacrifice a creature. When you do, exile target nonland permanent.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Enchant creature
Enchanted creature gets +0/+1 and has hexproof.
Mirage {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.)

Gain control of target non-Pirate, non-Rogue creature until end of turn. Untap that creature. It gains haste until end of turn. Pirates and Rogues you control get +1/+0 until end of turn.

When Press-Gang Recruiter enters, create a Treasure token.
{5}, {T}, Sacrifice an artifact: Gain control of target artifact or creature until end of turn. Untap that permanent. It gains haste until end of turn. Activate only as a sorcery.

Harmony — Exile another target creature until Pretentious Performer leaves the battlefield.
When Pretentious Performer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Search your library for a creature card, reveal it, put it into your hand, then shuffle. Then if you control a creature with power 4 or greater, you may pay {4}. If you do, you may put a creature card from your hand onto the battlefield.

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Haste
At the beginning of your end step, return Preying Mantis to its owner's hand.

Counter target spell unless its controller pays {1} for each card in their graveyard.

{1}, Sacrifice a creature: Each opponent loses 1 life.
Whenever a creature dies, you gain 2 life.

Destroy target creature with power 3 or greater.