msem-instigator

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}.

({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.)

({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}.

{T}: Add {C}.
{1}, {T}, Return Collapsing Ground to its owner's hand: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{5}{B}, {T}, Sacrifice Collapsing Ridges: Return target creature card from a graveyard to the battlefield under your control. Activate only as a sorcery.

Combined Generator can't be blocked except by three or more creatures.

Enchant creature
Enchanted creature must be blocked if able.

{T}: Add one mana of any color in your commander's color identity.

{T}: Add {C}.
{T}: Untap target legendary creature you control. Activate only once each turn.

{T}: Add {G} or {W}. You lose 1 life unless you have less life than an opponent.