msem-instigator

Target creature can't block this turn.
Draw a card.

Target creature gets +3/+3 and gains trample until end of turn.
Reconstruct {3}{G} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Enchant creature or planeswalker
Enchanted permanent can't attack or block and loses all abilities.

You mill two cards, draw two cards, lose 2 life, and create two Treasure tokens. (They're artifacts with “{T}: Sacrifice this permanent: Add one mana of any color.”)

Choose two —
• Destroy target artifact.
• Discard a card, then draw a card.
• Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Choose two —
• Create a 6/6 blue Kraken creature token.
• Take an extra turn after this one.
• End the turn.
Exile Crack in Time.

This spell has flash as long as you control a permanent with flash.
Put target nonland permanent on top of its owner's library.

Wanderlust — This spell costs {2} less to cast as long as you control four or more differently named lands.
Crackle Across Kahembo deals X damage to target creature or planeswalker.

Resolute — Whenever Crackling Agama deals combat damage to a player, if Crackling Agama's power is greater than its base power, that player sacrifices an artifact or enchantment.

When Crackling Palm Ascetic enters, target creature gains double strike until end of turn.

{1}{R}, Sacrifice Crackling Seaform: Counter target spell unless its controller has Crackling Seaform deal 3 damage to them.

Enchant land
When Cradle of Civilization enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Enchanted land has “{T}: Add one mana of any color.”

Cradle of Corruption enters tapped.
Whenever a creature dies, put a creation counter on Cradle of Corruption.
{T}, Remove ten creation counters from Cradle of Corruption and sacrifice it: Put up to two target creature cards from graveyards onto the battlefield under your control. Activate only as a sorcery.

{3}, {T}: You may put an artifact card with mana value 3 or less from your hand onto the battlefield. This ability costs {1} less to activate for each other artifact you control.

For each creature you control, create a token that's a copy of it. They gain haste. Sacrifice them at the beginning of the next end step.

Crafted Coast enters tapped unless another player controls a land that could produce {W} or {U}.
{T}: Add {W} or {U}.

Equipped creature gets +2/+0 and has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Crafter's Mistake deals 1 damage to target player or planeswalker. That player or that planeswalker's controller sacrifices an artifact.

Exile up to two target permanents you control, then return those cards to the battlefield under their owner's control.
Audition for blue. (Create a 1/1 Construct Actor creature token, a Wizard Role giving 2/2 and prowess, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

This spell costs {X} less to cast, where X is 20 minus your life total.
First strike, menace, trample

Flying
Cragstalker Eagle gets +2/+2 as long as you've cast a creature spell and a noncreature spell this turn.
You may cast Adventure spells and spells with Adventures from your hand as though they had flash.

Menace
Whenever you sacrifice an artifact or creature, Crain's Crew gets +1/+1 until end of turn.

Whenever Crain's Crony enters or attacks, reveal the top card of your library and put it into your hand. You lose life equal to that card's mana value.
At the beginning of each end step, if you didn't lose life this turn, you lose the game.

Prowess
When Cramming Student enters, conjure ten cards named Fatigue and shuffle them into your library. (They're colorless sorceries that cost {2} and have “Draw a card.”)
Instant and sorcery spells you cast cost {1} less to cast.