msem-instigator

When Caravan Guard enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

Sacrifice Caravan Merchant: Add {R}{R}.

Haste
Whenever Carnival Daredevil deals combat damage to a player, exile the top card of your library.
Duet — You may play cards exiled with Carnival Daredevil as long as you control exactly two tapped creatures.

Flying
When Carrier Familiar enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Flying
Whenever Carrier Pigeon attacks or blocks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Flying
When a creature you control scavenges Carrion Courier, put a flying counter on that creature.
Scavenge {2}{B} ({2}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

When Carrion Gourmet enters, each player sacrifices a creature.
Whenever another creature dies, put a +1/+1 counter on Carrion Gourmet.

If a source would deal damage to a creature in Cascading Zhenzu's pack, prevent 1 of that damage. (Two or more creatures you control with equal power are in a pack.)
{U}: You may switch Cascading Zhenzu's power and toughness until end of turn.

Whenever another creature or enchantment you control enters, you gain 1 life.
{3}{W}{W}, Pay 5 life: Castigated Sister becomes a 5/5 Angel Horror with flying. (This effect doesn't end at end of turn.)

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Whenever Cauldish Arrogant becomes blocked by one or more creatures, reveal the top card of your library. Cauldish Arrogant deals damage equal to that card's mana value to each creature blocking it. Then put that card into your hand.

Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Cauldish Warmonger attacks, create a 1/1 white Soldier creature token that's tapped and attacking.

Haste
Caulte Axeslinger gets +2/+2 as long as any opponent lost exactly 3 life this turn.

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

When Caustic Lurker dies, target player loses 1 life.

Whenever a Soldier or Knight you control enters, you may sacrifice Ceanne's Dawnbringer. If you do, put your choice of two different counters on that creature from among +1/+1, first strike, lifelink, and vigilance.

Ceanne, Shield of Caerdyne enters with your choice of a +1/+1, first strike, lifelink, or vigilance counter.
Counters remain on Ceanne as it moves to any zone other than a player's hand or library.
{3}{G/W}: For each kind of counter on Ceanne, put a counter of that kind on another target creature you control. Activate only once each turn and only as a sorcery.

Whenever a creature enters, if it entered from a graveyard or a player cast it from a graveyard, return Ceaseless Stalker from your graveyard to the battlefield at the beginning of the next end step.

Haste
Whenever this creature attacks, you may discard a card. If you do, draw a card.

Whenever you cast a spell, if it isn't your main phase, create a 1/1 white Monk creature token, then creatures you control get +1/+1 until end of turn.

Prowess, prowess, prowess
Noncreature spells you cast cost {1} less to cast.

Flash
When Cephalovorous Flukes enters, counter target spell or ability that targets you or a permanent you control.

As long as you control three or more creatures with the same name, Scouts and Wizards you control can't be blocked.
A deck can have any number of cards named Ch'aska Walla Chasqui.

Haste
Winnow (Damage dealt to this creature also causes you to lose that much life.)

Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Champion of the Fae.