msem-instigator

Menace
Whenever you sacrifice an artifact or creature, Crain's Crew gets +1/+1 until end of turn.

Prowess
When Cramming Student enters, conjure ten cards named Fatigue and shuffle them into your library. (They're colorless sorceries that cost {2} and have “Draw a card.”)
Instant and sorcery spells you cast cost {1} less to cast.

When Crane-Style Ascetic enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Put a +1/+1 counter on target creature you control.

{1}{R}: Crashcaller Nereid gets +1/+0 and gains trample until end of turn.

Resolute — At the beginning of combat on your turn, if Crazed Swashbuckler's power is greater than its base power, it deals 1 damage to target creature defending player controls. That creature can't block this turn.

Trample
Whenever Crazed Wildlings deals combat damage to a player, create a 1/1 red Goblin creature token.

Bloodprice—Reappropriate red. (You may cast this spell by sacrificing a creature and exiling two red cards from your hand and/or graveyard.)
Haste
Whenever Creed's Desperado attacks, if defending player has more cards in hand than you, exile the top card of that player's library. You may cast it as long as you control a Warrior, and you may spend mana as though it were mana of any color to cast it.

Whenever Crescent Crasher attacks, put a +1/+1 counter on target attacking creature with lesser power.

When Crimson Curtain Favored enters, starting with you, each player may discard any number of cards. When each player is finished discarding, choose one —
• Crimson Curtain Favored deals damage to each player equal to the number of cards in their hand.
• Each player draws a card for each card they discarded this way.

When Crinster Blacksmith enters, nourish 2. (To nourish 2, either put two +1/+1 counters on this creature or create two 1/1 white Citizen creature tokens.)

Trample
Whenever Crocheted Buddy attacks, if it's enchanted or you cast a spell that targeted it this turn, create a 1/1 colorless Construct Actor creature token.

When Crooked Merchant dies, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Flash
When Crossroads Harrier enters, it deals 2 damage to target opponent or permanent an opponent controls unless that player has you draw a card.

At the beginning of combat on your turn, put a +1/+1 counter on Crosswind Cutter if it's a creature.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Crusher Beetle can't be blocked by more than one creature.

{1}{B}, Discard Crusher Claw: Target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Death knell — Put a trample counter on target creature you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Sacrifice a creature: Put a +1/+1 counter on Crushing Victor. Activate only as a sorcery.

When Crystalline Golem enters, choose a color. You gain 1 life for each permanent of that color you control.

Flash (You may cast this spell any time you could cast an instant.)
When Culi-Sae Transfigurer enters, switch target creature's power and toughness until end of turn.

Whenever Culling Claw attacks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

{T}: Add {C}.
Whenever Cunning Chanter becomes tapped, each opponent mills a card.

First strike
Aura spells and spells with fabled you cast cost {1} less to cast.
Equip costs you pay cost {1} less.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
At the beginning of each player's upkeep, put a -1/-1 counter on target creature that player controls.

Pressure {1}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
When Cuxuri Harbinger enters, draw a card.

Menace
Whenever CySec Blacksuit deals combat damage to a player or planeswalker, create a Function token with “Choose a nonland card exiled by this spell. For as long as that card is exiled, you may cast it and you mana of any type can be spent to cast that spell.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)