msem-instigator

Menace (This creature can't be blocked except by two or more creatures.)
Cycling {R} ({R}, Discard this card: Draw a card.)

Create three 1/1 blue and red Pirate creature tokens with haste.

Whenever another creature you control enters, you may have it gain haste. If you do, return it to its owner's hand at the beginning of the next end step.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Sacrifice Bonetooth Darter: Counter target instant, planeswalker, or sorcery spell unless its controller pays {1}.

Enchant creature
When Bramble Armor enters, put a +1/+1 counter on enchanted creature.
{G}, Sacrifice Bramble Armor: Enchanted creature gains indestructible end of turn. Tap it.

Whenever Breakneck Barque becomes blocked by a creature, Breakneck Barque deals 3 damage to that creature.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

When Bridled Narwhal enters, you gain 5 life.

Brilliant Runepearl enters tapped.
Whenever you cast a permanent spell, you gain 1 life.
{T}: Add one mana of any color. Spend this mana only to cast permanent spells.

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 you draw a card, you may have target player mill two cards.

When Broadside Raider enters, create a 1/1 blue and red Pirate creature token with haste.

This spell costs {1} less to cast for each artifact and/or enchantment you control.

Whenever a creature you control becomes the target of a spell or ability, counter it unless its controller pays {1}. Whenever they do, put a +1/+1 counter on Brushcover Elf. (This includes your spells and abilities.)

Concord — Whenever Bubbledome Captain attacks, if there are four or more card types among permanents you control, each other attacking creature gets +1/+1 until end of turn.

When Bubbledome Chorister enters, create a green Aura enchantment token named Sanctum's Gift attached to target creature. The token has enchant creature and “Enchanted creature has ‘{T}: Add {G} for each enchanted creature you control.'”

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Concord — As long as there are four or more card types among permanents you control, Bubbledome Waveblade gets +1/+1.

When Bubblespout Sentry enters, look at the top card of your library. You may put it into your graveyard.

When Bug Catcher enters, create a 1/1 green Insect creature token.
Whenever a nontoken Insect you control dies, create a 1/1 green Insect creature token.

Pressure {B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Search your library for a card, put it into your graveyard, then shuffle. You gain 2 life.

Vanishing 3 (This permanent enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a time counter is removed from Burning Heels, exile the top card of your library. Until end of turn, you may play that card.

Target creature gets +4/+2 and gains trample until end of turn.

Whenever Bygone Wreck deals combat damage to a player, you may sacrifice it. If you do, create five Treasure tokens.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

Flying
When Cadre Hawk enters, you may search your library and/or graveyard for a card named Cadre Hawk, reveal it, and put it into your hand. If you searched a library this way, shuffle.

Return up to two target creatures and/or artifacts to their owners' hands. For each permanent returned to its owner's hand this way, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Flash
When Cane Dancer enters, you may cast target blue instant or sorcery card with mana value 2 from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.