msem-instigator

Target creature you control gains protection from everything until end of turn.

This spell costs {1} less to cast for each creature you attacked with this turn. (Those creatures don't have to still be on the battlefield.)
Flying

{W}, {T}: Tap target creature.

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.

When Cloister enters, exile another target nonland permanent you control and target nonland permanent you don't control until Cloister leaves the battlefield.
{2}{W}, Sacrifice Cloister: You gain 5 life.

Stampede — Whenever Cloud's Roar Avenger and a creature with greater power attack, tap up to one target creature.

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Flying
When Cloudheath Sentinel enters, return target artifact card with mana value 2 or less from your graveyard to the battlefield.

Flying, lifelink
When Cloudshaper Pilgrim enters, return target creature or enchantment card with mana value 3 or less from your graveyard to your hand.

When Coalition Apothecary enters, you gain 1 life for each nonland permanent you control.

Target creature you control gains hexproof and indestructible until end of turn. If it's a Knight or Soldier, put a +1/+1 counter on it.

When Coercive Cardinal enters, choose an opponent. That player may have you gain 5 life. If the player doesn't, create two 1/1 white Cleric creature tokens.

Equipped creature gets +1/+1 and has vigilance.
Equip {1}

Flash
When Collapsed Mine enters, exile another target nonland permanent until Collapsed Mine leaves the battlefield.

First strike

Create a 1/1 colorless Construct Actor creature token for each creature you control.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Choose one —
• Create two 1/1 white Soldier creature tokens.
• If you spent three or more mana to cast this spell, create five 1/1 white Soldier creature tokens.

Flash
When Colpah Charmer enters, you may tap or untap target creature.

Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has vigilance.

Whenever Combat Technician attacks, create a 1/1 colorless Servo artifact creature token that's tapped and attacking. Then Combat Technician gets +1/+1 until end of turn for each artifact you control.

Choose target creature you control, then choose two —
• Put a +1/+1 counter on it.
• Put a lifelink counter on it.
• That creature gains indestructible until end of turn.

Whenever a -1/-1 counter is put on a creature you control, you gain 1 life.
{1}{B}, Pay 1 life: Untap target Cleric. You may remove a -1/-1 counter from that creature.

Flash
When Comforting Presence enters, return target spell with mana value 2 or less to its owner's hand.
Whenever an opponent casts their second spell each turn, draw a card.

Lifelink
Partner with Imperator Valtasius (When this creature enters, target player may put Imperator Valtasius into their hand from their library, then shuffle.)
At the beginning of your upkeep, return target Soldier card from your graveyard to your hand.