msem-instigator

Whenever Bloodthirsty Insurgent attacks, it gets +2/+0 until end of turn.

Target creature gets +1/+0 and gains first strike until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

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

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

At the beginning of each player's end step, if they aren't horrific, Bloody Valentine deals 2 damage to that player. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Menace
Revive {1}{R} ({1}{R}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Destroy target artifact or land.

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.

Menace
When Bogborn Exorcist enters, you may discard a card. When you do, exile target instant or sorcery card with mana value 3 or less from an opponent's graveyard. Copy that card. You may cast the copy without paying its mana cost.

First strike
{T}: Bogclaw Sniper deals 2 damage to target blocking creature.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Target creature you don't control fights target creature you control, then fights up to one other target creature you don't control.

Whenever Bold Vanquisher attacks, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Trample

Damage can't be prevented.
At the beginning of your upkeep, Bomb Juggler deals 3 damage to target player chosen at random.

Target creature and all other creatures with the same name as that creature get +2/+0 until end of turn.

When Bone Pit Raptor enters, other creatures you control get +1/-1 until end of turn.
Revive {2}{R} ({2}{R}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

This spell costs {2} less to cast if you control a creature with power 4 or greater.
Bonk deals 4 damage to any target.

When Borderland Garrison enters, it deals 1 damage to up to one target creature and 1 damage to you.

Assault {R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Borsuppa Outrider assaults, it deals 2 damage to each opponent.

Whenever Borsuppa Roughrider attacks, create a colorless Desert land token named Scoured Path with “{T}: Add {R}.” Sacrifice that token at the beginning of the next end step.

Menace (This creature can't be blocked except by two or more creatures.)
Assault {R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
When Bottled Lightning enters, it deals 3 damage to any target. Scry 1.

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.

Harmony — Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”
When Bouquet Singer enters, harmonize. (Trigger up to one harmony of one permanent you control.)