msem-instigator

Concord — Whenever Chitinborn Sentry attacks, if there are four or more card types among permanents you control, prevent all damage that would be dealt to target attacking creature this turn.

{1}, Sacrifice a creature: Put a +1/+1 counter on Chitterrax, then each opponent loses 1 life and you gain 1 life.

Enchant creature
Enchanted creature gets -2/-2.
Mirage—{B}, Discard a card. (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Enchant creature
When Chords of Order enters, put a +1/+1 counter on enchanted creature.
Whenever enchanted creature attacks, tap up to one target creature without a +1/+1 counter on it, then untap up to one target creature with a +1/+1 counter on it.

When Chroma's Guidance enters, create a 2/2 green Wolf creature token.
Whenever you create a creature token, put a +1/+1 counter on it.

When Chronic Traitor enters, each player sacrifices a creature. If Chronic Traitor's paranoia cost was paid, each player sacrifices two creatures instead.
Paranoia {2}{B}{B} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

{2}, {T}, Sacrifice Chronomancer's Bauble: For each permanent with a time counter on it, you may put a time counter on that permanent or remove a time counter from it.

At the beginning of your upkeep, target player mills two cards. If your main library has five or fewer cards in it, that player mills their library instead.

{2/R}{2/R}: Churning Rough-Roller gets +1/+1 and gains double strike until end of turn.

When Churning Sandwurms enters, remove all counters from target permanent. Put a +1/+1 counter on Churning Sandwurms for each counter removed this way.

When Churning Spellroot enters, create three 1/1 black Worm creature tokens.

Flying
Whenever Circumspect Flock perseveres, create a 1/1 white Bird creature token with flying. (A creature perseveres when it survives damage.) (A creature perseveres when it survives damage.)

Citadel Bagworm gets +0/+1 for each card in your graveyard.
{B}, Discard a card: Switch Citadel Bagworm's power and toughness until end of turn.

{3}{G}: Search your library and/or graveyard for an Aura card, reveal it, and put it into your hand. If you search your library this way, shuffle.
{1}{U}: Untap target creature.

Target creature attacks or blocks this turn if able.
Forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Armed — Other Goblin creatures you control get +1/+1 and have haste as long as Clanleader of Beragnos is equipped.

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

Whenever you cast an instant or sorcery spell, you may exile that card instead of putting it anywhere else as it resolves.
At the beginning of your upkeep, Clash Reactor deals X damage to each opponent, where X is the number of colors of cards exiled with Clash Reactor.

Target creature fights another target creature. (Each deals damage equal to its power to the other.)

Whenever a creature enters under an opponent's control, you may have that player lose 1 life.
Unveil {2}{B}{R} ({2}{B}{R}: Transform this. Unveil only as a sorcery.)

This spell costs {1} less to cast for each card you've discarded this turn.
Draw three cards.

Sacrifice a creature: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

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

Target creature you control gets +1/+1 until end of turn. It deals damage equal to its power to target creature you don't control.

Whenever you cast an instant or sorcery spell, Clever Infiltrator gets +2/+0 until end of turn and can't be blocked this turn.