msem-instigator

{T}: Add {C}.
{T}, Sacrifice Cave of Pleonexia: Destroy target nonbasic land an opponent controls. You and that player each create a Treasure token. Activate only as a sorcery and only if that land's controller controls four or more lands. (A Treasure token is an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

First strike
Whenever a creature blocks Celestial Conscript, put a -1/-1 counter on that creature.

{T}: Add {C}.
Civilized — {T}: Add {C}{C}. Activate only if you control an artifact, a creature, and an enchantment.

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

{T}: Add {C}.
{T}: Add one mana of any color among creatures and planeswalkers you control.
{T}: Target player may gain control of target permanent you own. (That player may choose not to.)

Chamber of Splendor enters tapped.
When Chamber of Splendor enters, you may pay {1}. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{T}: Add {C}.

{T}: Add {C}.
{T}: Add one mana of any color that a basic land you control could produce.

Charbroiled Core enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Charred Marsh enters tapped unless you control a Mountain.
{T}: Add {B} or {G}.

Chartered Treasury enters tapped.
When Chartered Treasury enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {R} or {G}.

Chigau Market Outskirts enters tapped. When it does, choose a creature card name.
{T}: Add {B}.
{1}, {T}, Sacrifice Chigau Market Outskirts: You may cast a creature spell with the chosen name from your graveyard this turn.

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell or activate an ability of a legendary permanent.

{T}: Add {C}.
{1}, {T}, Sacrifice Chikyu League Arena: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Chiseled Cliffside enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

During your opponents' turns, Chroma, the Faerie Circle has all basic land types in all zones.
Chroma, the Faerie Circle enters tapped.

Equipped creature has haste.
Sacrifice Cinderblade: Equipped creature gains +2/+2 until end of turn.
Equip {1}

As Citadel Gates enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}, {R}, or {G}.

{T}: Add {C}.
{1}{C}{C}, {T}: Return target legendary creature to its owner's hand.

{T}: Add {C}.
{3}, {T}, Sacrifice City Gate: Put two +1/+1 counters on target creature you control that attacked this turn.

{T}, Pay 1 life: Add {W} or {U}.
{1}, {T}, Sacrifice Cleared Vault: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Cliffside Entrance enters tapped unless you have 15 or less life.
{T}: Add {R} or {W}.

Clocktower Hideout enters tapped.
When Clocktower Hideout enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {B} or {R}.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
Tap four untapped creatures you control: Unlock Clockwork Astrolarium. If the revealed card is white, put it into your hand. Otherwise, put it on top of your library.

{T}: Add {C}.
{T}, Pay 1 life: Add {W} or {B}.