msem-instigator

Whenever a player casts a spell, each opponent mills a card.

Create a 1/1 colorless Construct artifact creature token. For each other card named Competing Design in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”

When Compose from Dreams enters, you may cast any number of cards named Fatigue from your hand and graveyard without paying their mana costs.
Whenever you cast a spell, each opponent loses 1 life. Then you may draw a card if that spell wasn't cast from your hand. Then add {U}{B}{R} if you don't own that spell.

If a player would draw one or more cards except for the first one they draw in each of their draw steps, they exile a card from their hand before they draw those cards.
{1}, {T}: Until end of turn, you may play target card exiled with Compromised Vault, and you may spend mana as though it was mana of any color to cast that spell.

When Compulsion's Voice enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.
Recite {1}{U}{R} (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.)

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, you lose 1 life and you draw a card.

Draw three cards. Then discard two cards unless you return a permanent you control to its owner's hand.

When Compulsory Studies enters, exile target creature until Compulsory Studies leaves the battlefield. Each player draws a card.

Discard a card: Concealed Slasher gets +1/+1 until end of turn and can't be blocked this turn.

Exile target creature you control, then return that card to the battlefield under your control. Scry 1.

Equipped creature gets +1/+0, has no name, and loses all non-Pirate, non-Rogue creature types.
{1}: Equipped creature gains the creature types and activated abilities of target creature and its name becomes that creature's name until end of turn.
Equip {1}

Shuffle your hand into your library, then draw X cards.

Concentrated Blast deals 5 damage to target creature.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Conchhorn Shinygrabber attacks, you may pay {1}. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{W}{U}{B}{R}{G}: Conchhorn Shinygrabber gets +3/+3 and gains lifelink until end of turn.

Spells you cast from exile cost {1} less to cast.

Draw two cards.
Menagerie — If there are five or more creature types among creatures you control, draw three cards instead.

{T}: Conchspear Hunter deals 1 damage to any target. Activate only if you control three or more artifacts.

Target creature gets -1/-1 until end of turn. Audition for black. (Create a 1/1 Construct Actor creature token, a Cleric Role giving 2/2 and lifelink, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

Destroy target creature. (Cast a copy of this spell once while this creature is on the battlefield.)

At the beginning of combat on your turn, you may exile a creature card from your graveyard. Then if a card exiled with Concoquo has flying, creatures you control gain flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Each player draws a card, then target player mills X cards, where X is the number of cards players have drawn this turn.

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

When Condemned Cavalier enters, create a white and black Aura Curse enchantment token named Profane March attached to target player. The token has enchant player and “Whenever a creature enchanted player controls attacks, that player loses 1 life and defending player gains 1 life.”

Counter target spell unless its controller pays {X}. Scry 2.

Whenever you cast an enchantment spell, create a 1/1 white and black Bird creature token with flying and vigilance.
Whenever three or more creatures you control deal combat damage to a player, that player sacrifices a creature. If they can't, they discard a card.