msem-instigator

Prowess
Unveil {2}{U}{R} ({2}{U}{R}: Transform this. Unveil only as a sorcery.)

Lifelink
When Bright-Eyed Adventurer enters, 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.)

Flying, haste
At the beginning of the end step, sacrifice Brightflame Phoenix.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Flash
When Brightsouled Guardian enters, return up to one target nonland permanent to its owner's hand.

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

Prowess, trample
Whenever Brilliant Diviner deals combat damage to a player, draw a card.

Flying
When Brilliant Griffin enters, target creature gets +2/+2 until end of turn.

Choose one —
• Brimstone Cleansing deals 4 damage to target tapped creature.
• Exile target enchantment.

{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.)

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

Foretell {1}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Brimstone Oration deals 2 damage to any target. If this spell was foretold, it deals 4 damage to any target instead.

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.)

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

Destroy target creature with flying.
Draw a card.

Target creature gets +3/+0 until end of turn. Mill three cards.

Trample
When Bringer of Armies enters, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

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

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

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.

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.

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

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.)