msem-instigator

Flying
When Cormoran, Raven Monarch enters, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.

({T}: Add {B}.)
Corpsebed enters tapped.
When Corpsebed enters, exile up to two target cards from graveyards.

(Transform this if it's not attached to a creature. Pay {3}{B} as a sorcery to unattach it.)
Enchant creature you control
Corrupted Mount's rider gets +5/+4 and can't block.

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/-1.
Whenever equipped creature dies, draw a card. This ability triggers only once each turn.
Equip {1}

{T}: Add one mana of any color.
{5}, {T}, Sacrifice Cosmic Chart: Search your library for a card, put it into your hand, then shuffle.

When Cosmic Contraption enters or leaves the battlefield, you may reveal a noncreature card you own from outside the game and put it into your hand.

Whenever you cast a spell, you may pay 3 life. If you do, draw a card.

Equipped creature gets +2/+1.
Whenever equipped creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability.
Equip {2}

{T}: Add one mana of any color.
{3}, {T}, Sacrifice Coveted Heirloom: Draw a card.
Tap three untapped artifacts you control: Return Coveted Heirloom from your graveyard to the battlefield.

As Coveted Tower enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {G}, {U}, or {R}.

Cradle of Corruption enters tapped.
Whenever a creature dies, put a creation counter on Cradle of Corruption.
{T}, Remove ten creation counters from Cradle of Corruption and sacrifice it: Put up to two target creature cards from graveyards onto the battlefield under your control. Activate only as a sorcery.

Cradle of War enters tapped.
{3}, {T}: You may put an artifact card with mana value 3 or less from your hand onto the battlefield. This ability costs {1} less to activate for each other artifact you control. Activate only as a sorcery.

You can't lose the game.
At the beginning of your upkeep, put Cradle of the Sun on the bottom of your library and your life total becomes 4.

Crafted Coast enters tapped unless another player controls a land that could produce {W} or {U}.
{T}: Add {W} or {U}.

Equipped creature gets +2/+0 and has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

{2}, Exile Cranial Archive: Target player shuffles their graveyard into their library. Draw a card.

Flash
When Cranial Glass enters, exile target card from a graveyard.
{7}, {T}, Sacrifice Cranial Glass: Copy the exiled card. You may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)

{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.)

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.

Flying
At the beginning of combat on your turn, create a 5/5 red Dragon creature token with flying and haste. That token attacks this combat if able.

You may have Crossroads Town enter tapped. If you do, search your library for a basic land card, reveal it, then shuffle and put that card on top.
{T}: Add {C}.

{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.

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}

You may play lands from your graveyard.

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