msem-instigator

Lands you control have “{T}: Add one mana of any color.”
{T}: Add one mana of any color.

At the beginning of each player's draw step, that player draws an additional card.
Spells cost {1} less to cast.
Players may spend mana as though it were mana of any color.

{2}, {T}, Sacrifice Chronomancer's Bauble: For each permanent with a time counter on it, you may put a time counter on that permanent or remove a time counter from it.

Whenever a player casts a spell, put a time counter on Chronovore Clock. Then if there are ten or more time counters on it, remove all time counters from it and end the turn.

{2/R}{2/R}: Churning Rough-Roller gets +1/+1 and gains double strike until end of turn.

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}.

{X}, {T}: Reveal the top card of your library. If its mana value is X or less, you may play it without paying its mana cost. Otherwise, put it into your hand. X can't be 0.

{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.

Whenever you cast an instant or sorcery spell, you may exile that card instead of putting it anywhere else as it resolves.
At the beginning of your upkeep, Clash Reactor deals X damage to each opponent, where X is the number of colors of cards exiled with Clash Reactor.

{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}.

Equipped creature has flying.
Equip {3}

Equipped creature has hexproof. (That creature can't be the target of spells or abilities your opponents control.)
Equip {0}

{T}, Tap an untapped creature you control: Choose one —
• Add one mana of any color.
• Target player loses 2 life.
• Target player gains 3 life.
• Target player mills four cards.

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.

Clockwork Gaucho enters with a +1/+1 counter on it.
Other artifact creatures you control get +1/+1 for each +1/+1 counter on Clockwork Gaucho.
{T}: Put a +1/+1 counter on Clockwork Gaucho.

{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}.

{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.)