msem-instigator

{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}.

{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 one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your first main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.

({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}.

Submerge each creature you control. At the beginning of the next end step, you may turn any number of face down creatures you control face up. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Trample, haste
Crew—Tap three untapped artifacts and/or creatures you control.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Other artifacts you control have extort.
Whenever a spell you control resolves, if it was extorted three or more times, each opponent discards a card and you draw a card.

Dominance — At the beginning of combat on your turn, if you control the creature with the greatest power or tied for the greatest power, you may pay {R}. If you do, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

When Cognitive Fumigator enters, target opponent reveals their hand. You may choose a nonland card from it and exile that card. If you do, that player draws a card.
Recite {2}{U} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Creatures have “Whenever this creature attacks or blocks, it fights another target creature.”

Whenever a land enters, Collapsing Realities deals 2 damage to each player.

{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.