msem-instigator

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

{1}{R}: Circus Firebreather gets +1/+0 until end of turn.

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.

Target creature attacks or blocks this turn if able.
Forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Whenever another creature you control enters, you gain 1 life.
{4}{W}: Return another target creature you control to its owner's hand.

Sacrifice a creature: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

{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.”)

Cast this spell only during your turn.
Draw a card. Then if an opponent cast a spell this turn, scry 1 and draw an additional card.

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

Equipped creature has flying.
Equip {3}

When Climber's Outfit enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Equipped creature has reach.
Equip {1}

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}.

({T}: Add {U}.)
Cloudbank enters tapped.
When Cloudbank enters, target creature gains flying until end of turn.

Cloudcover Heights enters tapped unless you control a Forest.
{T}: Add {R} or {W}.

({T}: Add {R}.)
As Cloudpeak Spires enters, you may pay 1 life. If you don't, Cloudpeak Spires enters tapped.
Basic lands you control have “{T}: Add {R}.”

({T}: Add {R} or {W}.)
Cloudsteel Summit enters tapped.
{1}, {T}: Add {R}{R} or {W}{W}.

Clutch Shot deals 2 damage to target creature or planeswalker. If you control six or more lands, Clutch Shot deals 4 damage instead.

{T}: Add {C}.
{1}: Clutch of the Coil becomes a 1/1 Snake creature with poisonous 2 until end of turn. It's still a land. (Whenever this creature deals combat damage to a player, that player gets two poison counters.)

Return target creature to its owner's hand.
Coalesce {4}{U}{U} (You may cast this from your graveyard for {4}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

({T}: Add {W}, {U}, or {B}.)
Coastal Dominion enters tapped.

Coastal Metropolis enters tapped unless you have 15 or less life.
{T}: Add {W} or {U}.