msem-instigator

At the beginning of your end step, mill two cards. Then if ten or more cards are in your graveyard, transform Bitter Duckling.

Whenever Blackfeather Cleric enters or attacks, exile target card from a graveyard. Put a +1/+1 counter on Blackfeather Cleric if it was a permanent card. Otherwise, you gain 1 life.
Surpass {5}{B} ({5}{B}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Double strike
Attain {3}{R} ({3}{R}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Exile target instant or sorcery card from your graveyard. Copy it. You may cast the copy. (Cast a copy of this spell once while this creature is on the battlefield.)

Vigilance
Blessed Suncrusher's power and toughness are each equal to your life total.

Put a +1/+1 counter on target creature you control.
Monument {1}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Blighted Unicorn can't block.
Ride {3}{B} ({3}{B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

When Blinding Fiddler enters, until your next turn, creatures can't attack you or a planeswalker you control unless their controller pays {2} for each of those creatures.
Unveil {3}{W}{U} ({3}{W}{U}: Transform this. Unveil only as a sorcery.)

Whenever Blood Constrictor becomes blocked by a creature, you gain life equal to that creature's toughness.

Destroy target creature that was dealt damage this turn. (Then exile this card. You may cast the creature later from exile.)

Flying, menace
Sacrifice a creature: Put two +1/+1 counters on Bloodclaw Demon. It gains indestructible until end of turn.

Flying
{1}, Sacrifice a creature: Put a +1/+1 counter on Bloodthirsty Manticore. It gains indestructible until end of turn. Tap it.
Surpass {4}{B}{R} ({4}{B}{R}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Flying, deathtouch, lifelink
Ride {1}{B} ({1}{B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)
You may activate Bonescourge Kazadrak's ride ability from your graveyard by sacrificing a creature in addition to paying its other costs.

Deathtouch

You may cast a spell with mana value 3 or less from your hand without paying its mana cost. (Then exile this card. You may cast the creature later from exile.)

[+1]: Boxue deals 1 damage to each opponent. You may draw a card, then discard a card.
[–1]: Create a Treasure token.
[–5]: Copy the next spell you cast this turn. You may choose new targets for the copy. (A copied permanent spell becomes a token.)

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.)

Wither (This deals damage to creatures in the form of -1/-1 counters.)
When you unveil Bramble Quickling, you may have it fight target creature.

At the beginning of your end step, if Bramblemane didn't attack this turn, transform it.

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.

Double your life total. (Then exile this card. You may cast the creature later from exile.)

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

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

{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.)