msem-instigator

When Boundary Hallowblade enters, create a white Aura enchantment token named Consecration Blessing attached to target land. The token has enchant land and “Enchanted land is named Hallowed Ground and has indestructible.”

{B}, {T}: Post a bounty on target permanent. (Put a bounty counter on that permanent. It has “When this permanent is put into a graveyard from the battlefield, each opponent draws a card” as long as it has a bounty counter on it.)
{B}, {T}, Pay 2 life: Destroy target creature with a bounty counter on it.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Bounty Crusher has trample as long as it's being blocked by a marked creature.

Untap target creature you control. It gets +4/+4 and gains reach until end of turn.

Counter target spell. Spells its controller casts cost {2} more to cast this turn.

[+2]: Discard a card at random. If you do, draw two cards.
[0]: Target creature's controller may pay X life. If they don't, you lose X life and gain control of it (Choose any number for X.)
[–3]: Flip a coin until you lose a flip or choose to stop flipping. For each flip you won, draw two cards and create a tapped Treasure token.

When you cast this spell, copy it. You may choose new targets for the copy. (Copies keep functions.)
Draw a card.

Branch Prowler can't be blocked except by creatures with flying.

Haste
You may exert Brash Charger as it attacks. When you do, creatures with power 1 or less can't block this turn. (An exerted creature won't untap during your next untap step.)

Sacrifice another creature: Brash Hunter deals 1 damage to any target.
At the beginning of your end step, if three or more creatures died this turn, transform Brash Hunter.

As Brave the Issbarrens enters, choose a color.
White creatures you control have protection from the chosen color. (This permanent can't be targeted, dealt damage, enchanted, or equipped by anything with that color.)

Haste
At the beginning of your end step, sacrifice Breach Runner unless you return another creature you control to its owner's hand.

Destroy target artifact or tapped creature.

Put a number of +1/+1 counters on target creature you control equal to that creature's power.
Spell mastery — If there are two or more instant or sorcery cards in your graveyard, you may have that creature fight another target creature. (Each deals damage equal to its power to the other.)

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.)

Breath of Hao'Tai deals 4 damage to any target.

{1}{G}: Target land you control becomes a 3/3 green Elemental creature until end of turn.
{1}{U}: Target enchantment you control becomes a 2/2 blue Nymph creature with flying until end of turn.

Breezerider has flying as long as you control a Nymph.
Breezerider has hexproof as long as you control another Monkey.

Deathtouch
When Brig of the Damned enters, return target creature card from your graveyard to your hand. If that card's mana value is 2, you may return it to the battlefield instead.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

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

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.

Destroy target creature with flying.
Draw a card.

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.

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.)

Ward {2}
Whenever Brunig enters or attacks, you may shuffle a card you own from outside the game into your library. If you do, you gain 2 life.
Brunig gets +2/+2 and has trample as long as your library contains at least forty cards more than the minimum deck size.