msem-instigator

Tap up to four target nonland permanents. Nonland permanents your opponents control don't untap during their controller's next untap step.

{2}{R}: Target creature can't block Brimstone Courser this turn.
Ride {3}{R}{R} ({3}{R}{R}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Defender
When Brine Duelist enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this permanent: Add one mana of any color.”)
{W}{U}{B}{R}{G}: Put a +1/+1 counter on Brine Duelist. It loses defender.

Whenever Brine Kelpie attacks, you may tap target creature an opponent controls.
Ride {2}{U} ({2}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

At the beginning of your upkeep, you may discard a land card. When you do, create a 2/2 green Wolf creature token.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
When Bristling Baron dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control.

Distribute three +1/+1 counters among up to three target creatures you control. Those creatures gain first strike until end of turn.

Broken Deathbringer gets +1/+0 as long as you have 10 or less life.
Broken Deathbringer gets +1/+0 as long as there are one or fewer cards in your hand.

When Broken Spirit enters, exile target creature an opponent controls until Broken Spirit leaves the battlefield.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Create two 1/1 green Insect creature tokens. (Cast a copy of this spell once while this creature is on the battlefield.)

Flying
You may reveal the second card you draw each turn as you draw it. Whenever you reveal a nonland card this way, copy that card. You may cast the copy. If you don't, Brutal Director deals 2 damage to any target. (You still pay the spell's cost.)

Destroy target creature. Its controller discards a card.

Whenever you cast an enchantment, instant, or sorcery spell, create a 1/1 blue Jellyfish enchantment creature token with slipstream. (It can't be blocked as long as only creatures with slipstream are attacking.)

Whenever you cast a spell for its showcase cost, create a 2/2 blue Drake creature token with flying.

{3}{U}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Untapped creatures you control get +0/+2.

Destroy all creatures. Each player shuffles their graveyard into their library.

{T}, Sacrifice a creature: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{T}, Sacrifice a Clue: Create a 3/3 green Elemental creature token.

At the beginning of your upkeep, reveal the bottom card of your library, then you may pay {B} and 3 life. If you do, put it into your hand. Otherwise, exile it.

Whenever an attacking creature you or a teammate controls dies, Burned Bounty deals damage equal to that creature's power to each opponent.

Destroy target land an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.
Draw a card.

Search your library for a card, put it into your graveyard, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Converge — Destroy up to X target artifacts or enchantments, where X is the number of colors of mana spent to cast Bury the Past.

When Bustling Bazaar enters, return target artifact, instant, or sorcery card from your graveyard to your hand.
Sacrifice a nontoken artifact: Create two tapped Treasure tokens.

({T}: Add {W}.)
Bustling Docks enters tapped.
{W}, {T}, Reveal a white card from your hand: Target creature gets +1/+0 until end of turn.