msem-instigator

When Collapsing Frame enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, Sacrifice Collapsing Frame: Draw a card.

Collapsing Ramparts deals damage to target creature equal to twice the number of Satrapies you control.

Haste
When Collapsing Star Viper enters, you may tap target permanent with mana value X or less.
At the beginning of your upkeep, return Collapsing Star Viper to its owner's hand.

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.

{T}: Add one mana of any color.
Augmented — Whenever a nontoken creature you control enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on it.

Whenever a token creature you control dies, each opponent loses 2 life.

Reach
When Colonial Effigy dies, create a 1/1 white Spirit creature token with flying.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
When Colpah Mystic enters, you may discard a card. If you do, creatures you control named Colpah Mystic get +2/+2 until end of turn.

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.

Put a +1/+1 counter on target creature you control. It can't be blocked by more than one creature this turn.
Whenever a creature you control attacks alone, return Come Out and Play from your graveyard to your hand.

When Commander of the Cavalry enters, you may search your library for a creature card with ride, reveal it, and put it into your hand. If you do, shuffle.
{X}, {T}: Put a creature card with ride and mana value X or less from your hand onto the battlefield transformed and attached to another target creature you control without a Steed attached to it.

Look at the top five cards of your library. You may reveal a land or Nomad card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
You may play an additional land this turn.

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}.”

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 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.

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.

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

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.

When Conduit of the Conflux enters, scry 2.
{T}: Add one mana of any color.

At the beginning of combat on your turn, you lose 1 life and rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

When Confident Traveler dies, create a 1/1 white Human creature token. If Confident Traveler was sacrificed, create two of those tokens instead.

When Confining Priest enters, exile another target creature with power 4 or less an opponent controls until Confining Priest leaves the battlefield. (That creature returns under its owner's control.)

Draw a card, then copy target activated or triggered ability you don't control. You may choose new targets for the copy.
Exile Confirm Hypothesis.

Target creature you control gets +1/+0 until end of turn. It fights target creature you don't control.