msem-instigator

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell with a creature type no creature you control has.

Enchant creature
When Crown of Spores enters, germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)
Enchanted creature gets +2/+2.

Equipped creature gets +2/+2.
Whenever equipped creature attacks, each opponent who controls more artifacts than you sacrifices an artifact. Opponents sacrifice creatures, enchantments, lands, and planeswalkers the same way.
Equip {1}{W}

Equipped creature gets +X/+X, where X is the number of cards in your graveyard.
Sacrifice a creature other than equipped creature: Equipped creature gains lifelink and indestructible until end of turn.
Equip {3}

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Other creatures you control with distorted get +2/+2.

Enchant creature
When Crowning Ceremony enters, draw a card.
Enchanted creature gets +1/+0.

You may play lands from your graveyard.

{2}, {T}: Draw a card. Crude Tablet doesn't untap during its controller's next untap step.

At the beginning of your upkeep, mill a card.
{B}, Sacrifice Cruel Consultation: Exile any number of cards from your graveyard. Create an X/X black Djinn Horror creature token, where X is the number of card types among cards exiled this way.

Reach
Scarecrow spells you cast cost {1} less to cast.

Flying
Cruel Fledgling enters with a +1/+1 counter on it if six or more cards are in your graveyard.

Whenever Cruising Schooner attacks, it gets +1/+1 until end of turn.
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.)

Crumbling Aqueduct enters tapped unless you control another Desert.
{T}: Add {U} or {B}.

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

({T}: Add {B} or {R}.)
Whenever Crumbling Precipice becomes tapped, you lose 1 life unless you control two or more basic lands.

Crumbling Shrine enters tapped. When it does, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this, then you may put that card into your graveyard.)
{T}: Add {G}.
{2}{G}{G}: Crumbling Shrine becomes a Nymph creature. (This effect lasts indefinitely.)

Crumbling Vestige enters tapped.
When Crumbling Vestige enters, add one mana of any color.
{T}: Add {C}.

Assault {3}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Crushclaw Pulverizer assaults, you may destroy target artifact or enchantment.

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.)

Enchant player
Whenever one or more creatures you control die, enchanted player loses 1 life and you gain 1 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 Crux Pinnacle enters, for each color, exile up to one target permanent of that color until Crux Pinnacle leaves the battlefield.
Whenever a player casts a spell, if there are five or more spells on the stack, you win the game.

Menace, haste, decayed (This can't block. When it attacks, sacrifice it at end of combat.)
At the beginning of combat on each of your turns, if you have three or more creature cards in your graveyard and haven't controlled a creature named Crypt Gnawer this turn, return Crypt Gnawer from your graveyard to the battlefield.

Deathtouch
When Crypt Strider enters, create a 1/1 black Skeleton creature token for each creature card in your graveyard.