msem-instigator

When Blisterbug dies, put two +1/+1 counters on target creature you control.

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

{1}, {T}, Sacrifice another creature: Put a +1/+1 counter on Bloodied Wulfhound.

Sacrifice a creature: Put a +1/+1 counter on Bloodlash Caravan. Then if it's the only creature you control, it gains indestructible until end of turn.

Target creature gets +3/+2 and gains trample until end of turn.

Blooming Vista enters tapped.
{T}: Add {R} or {G}.
{1}, {T}: Add one mana of any color.

Blossoming Sands enters tapped.
When Blossoming Sands enters, you gain 1 life.
{T}: Add {G} or {W}.

Whenever a creature dies, put a +1/+1 counter on Bog Apex.

Enchant creature
When Bogfume Pact enters, each opponent sacrifices a creature.
When enchanted creature dies, return it to its owner's hand.

Haste
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Bolstered Guardian. It loses this ability and gains “Whenever this attacks, it deals 2 damage to each of up to two targets.”

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Deathtouch

Other Hounds you control get +1/+1.

Whenever Bourasan Street Watch attacks, you may pay {W}. If you do, Bourasan Street Watch gains indestructible until end of turn.

Target opponent discards two cards. (Cast a copy of this spell once while this creature is on the battlefield.)

Gain control of target permanent. (Cast a copy of this spell once while this creature is on the battlefield.)

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

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.)

Brushfire deals 3 damage to target creature. If that creature would die this turn, exile it instead.

Flash
Enchant creature
Enchanted creature gets +1/+1 and has hexproof.

You may cast this spell as though it had flash if it targets a creature or planeswalker.
Burning Up deals X damage to any target, where X is the number of basic land types among lands you control.

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

Butcher deals 3 damage to target player. (Cast a copy of this spell once while this creature is on the battlefield.)

Deathtouch
Once each turn, you may cast a creature spell from your graveyard by paying life equal to its mana value rather than paying its mana cost.

Bwema, the Ruthless enters with your choice of two different counters on it from among menace, first strike, vigilance, and lifelink.