msem-instigator

First strike
Whenever Creed, Eternal Straggler attacks, exile the top card of your library. You may play that card this turn, and that spell costs {2} less to cast.

Hexproof
Whenever one or more cards are put into your graveyard from anywhere, Creeping Hidebehind gets +1/+0 until end of turn.

Harmony — Target player mills four cards.
When Creeping Pianist enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Target player discards two cards.
Kindle 2—{1}{B}{B} ({1}{B}{B}, Exile this card from your graveyard: Create two 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

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

{T}: Add {C}.
{3}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

When Crescent of the Harvest Moon enters or whenever equipped creature attacks, exile up to one target card from a graveyard.
Equipped creature gets +1/+1.
{X}: Equipped creature becomes a copy of a permanent card with mana value X or less exiled with Crescent of the Harvest Moon until end of turn (even if this becomes unattached). Activate only as a sorcery.
Equip {2}

Return target nonland permanent to its owner's hand.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flying
Wanderlust — When Crest Skimmer enters, if you control four or more differently named lands, draw a card.

Flying
Death knell — Put a flying counter on target creature you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

This spell costs {1} less to cast for each Desert you control.
When Crested Crustacean enters, return target permanent to its owner's hand.

Cresting Bay enters tapped unless you control a basic Island.
{T}: Add {U}.
{2}{U}{U}: Until end of turn, Cresting Bay becomes a 3/3 blue Elemental creature with “Whenever this creature attacks, you may draw a card then discard a card.” It's still a land.

When Gillo enters, reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. If it's a creature card, put it into your hand.
As long as you control five or more creatures with different names, creatures you control get +1/+1 and have trample.

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.

Flying, haste
When Crimson Hellmaw enters, it deals 3 damage to any target.
Revive {5}{R}{R} ({5}{R}{R}, 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.)

Haste
{R}{R}{R}, Discard your hand, Sacrifice Crimson Knight: Draw three cards.

Create three 2/2 red Noble creature tokens with disgraced 1. (Each enters with a -1/-1 counter. Whenever one deals combat damage to a player, remove all -1/-1 counters from it.)

Distribute four -1/-1 counters among any number of target creatures.

Crimson Sunrise deals 4 damage to each creature. Each player sacrifices four nonbasic lands.

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.)

When Crinster Falconer enters, create a 1/1 blue Bird creature token with flying.

Defender
{T}: Another target creature gains haste until end of turn.

Vigilance
Crinster Ranger enters with X +1/+1 counters on it, where X is the number of +1/+1 counters among other creatures you control.

Whenever another creature named Crinster Sheepdog enters, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)

Rapport — Whenever Crinster Stitcher and at least one other creature you control become tapped, tap target creature.