msem-instigator

First strike
Other Rogues you control get +1/+0 and have first strike.
{2}, Sacrifice a permanent: Return target Rogue card from your graveyard to your hand.

Alpha (You may have this creature enter the battlefield with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Brazen Chimera can't be blocked except by three or more creatures as long as it has a +1/+1 counter on it.

Haste
Whenever one or more creatures attack, you may discard a card. If you do, draw a card.

When Breaker of Secrets enters the battlefield, each player mills three cards from each of their libraries.
Recite {U} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters the battlefield or if it would leave the battlefield.)

Choose a creature type. Return up to two target creature cards of the chosen type from your graveyard to your hand.

If you would draw a card, you may instead choose creature or land and exile cards from the top of your library until you exile a card of the chosen kind. Put that card into your hand and put all other cards exiled this way on the bottom of your library in a random order.

When Briarform Apothecary enters the battlefield, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Sacrifice a token: Briarform Apothecary gets +2/+2 until end of turn.

This spell costs {2} less to cast if you control a transformed permanent.
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Lifelink
When Bright-Eyed Adventurer enters the battlefield, rediscover an enchantment card. (Look at the top card of your library. You may reveal it and put it into your hand if it's an enchantment card. Otherwise, put it back or into your graveyard.)

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

Brilliant Runepearl enters the battlefield 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.

{T}: Brimstone Grenadiers deals 1 damage to target player.
Whenever you cast an instant or sorcery spell, untap Brimstone Grenadiers.

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

Whenever Bristled Wolverine attacks, it gets +1/+1 until end of turn.

Bristling Skoki has first strike as long as it's attacking.
Whenever Bristling Skoki blocks a creature, you may have it deal damage equal to its toughness to that creature.

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

Whenever you play a land, you may search your library for a land card that shares a subtype with it, put it onto the battlefield tapped, then shuffle.

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

Double strike
Whenever you cast a noncreature spell, you may choose one that hasn't been chosen —
• Tap or untap target permanent.
• Draw two cards, then discard a card.
• Creatures you control get +1/+1 until end of turn.

Choose target creature. Brutal Descent deals 2 damage to each creature other than the chosen creature.
Ferocious — If the chosen creature has power 4 or greater, Brutal Descent deals 4 damage to each creature other than the chosen creature instead.

Brutal Struggle deals 2 damage to any target. Put a +1/+1 counter on up to one target creature.

Whenever one or more creatures you control deal combat damage to a player, you may destroy target artifact or enchantment that player controls.
Whenever you cast a green creature spell, create a 3/3 green Wurm creature token with trample.

Whenever another creature enters the battlefield, Brutish Champion fights that creature.

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.)

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