msem-instigator

Civilization's Cost deals damage to each player equal to the number of nonbasic lands that player controls.
Flashback {R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Draw a card, then each player draws a card.

Search your library for a basic land card and put that card onto the battlefield, then shuffle.
{5}{G}{W}, Exile Claim for Civilization from your graveyard: Create a 6/6 colorless Golem artifact creature token. Activate only as a sorcery.

This spell costs {3} less to cast if it targets a permanent with mana value 3 or less.
Gain control of target nonland permanent until end of turn. Untap it. It gains haste until end of turn.

When Clawing Shaman enters from your graveyard, you may exile it. If you do, return all creature cards from your graveyard to the battlefield.
{4}{B}{B}{B}, Sacrifice a creature: Return Clawing Shaman from your graveyard to the battlefield. Activate only as a sorcery.

Exile target nonland permanent.

{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.”)

Soldiers you control get +1/+1.
Whenever one or more creatures attack, create a 1/1 red Soldier creature token.

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}.

Choose target creature you control. Double its power and toughness until end of turn. That creature deals X damage divided as you choose among any number of target creatures and/or planeswalkers your opponents control, where X is its power.

When Climbing the Oldest Mountain enters, draw a card, then choose a card name.
Whenever a creature you control with the chosen name deals combat damage to a player, put two +1/+1 counters on it.

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

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.

Enchant artifact
Enchanted artifact is a creature with base power and toughness 3/3 in addition to its other types.
Enchanted artifact has prowess and “Once each turn, when you cast a noncreature spell, you may untap this artifact.”

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

Flying
{U}: Put Cloud Sovereign on top of its owner's library.
Foresee — As you draw Cloud Sovereign, you may reveal it and pay {1}{W}. When you do, create a 1/1 white Bird creature token with flying.

Flying
Whenever you cast a spell, create a 1/1 blue Boar Dragon creature token with flying.

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

Flying
Whenever Cloudfisher deals combat damage to a creature, gain control of that creature for as long as you control Cloudfisher.
Whenever Cloudfisher deals combat damage to a player, gain control of target land that player controls for as long as you control Cloudfisher.

({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}.

Flash
Flying
You may cast creature spells with flying as though they had flash.
Whenever another creature with flying you control enters, this creature gets +1/+1 until end of turn.

When Cloven Forms enters, reveal the top three cards of your library. Put all creature cards revealed this way into your hand and the rest into your graveyard.
{5}{G}{G}{G}, Exile Cloven Forms: Put a creature card from or hand or command zone onto the battlefield. Create a token that's a copy of it, except the token isn't legendary.

{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.)