msem-instigator

Advance {1}{R} (Cast this for {1}{R} to advance it as it enters. {1}{R}: Advance this as a sorcery.)
Whenever Blitz Breaker advances, its power becomes equal to the amount of noncombat damage that's been dealt to your opponents this turn. (This effect lasts indefinitely.)

Flying
Whenever Blizzard Dragon attacks, tap an artifact, a creature, and a land defending player controls. They don't untap during their controller's next untap step.
At the beginning of each opponent's upkeep, that player sacrifices a tapped permanent.

Target player discards two cards.
Orchestrate {1}{B}{B} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Menace (This creature can't be blocked except by two or more creatures.)
Blood Fiend can't block.
{1}{B}, Pay 3 life: Return Blood Fiend from your graveyard to the battlefield. It gains haste.

Nonbasic lands have “Whenever this land becomes tapped, you lose 1 life unless you sacrifice this land.”

Whenever equipped creature attacks, choose target creature defending player controls. Destroy that creature at end of combat.
Equip {4}

When Blood Jade Prophet enters the battlefield, reveal the top three cards of your library. For each card revealed this way, you may pay 3 life. If you do, put that card into your hand. Otherwise, put it into your graveyard.

At the beginning of your upkeep, each player sacrifices a nonbasic land.

Improve {1}{R} ({1}{R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
As long as Bloodbelly Glutton is embattled, it has first strike, menace, and haste. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

{B}, Discard a card: Bloodbraid Ritualist gains indestructible until end of turn. Tap it.
At the beginning of your upkeep, you may have Bloodbraid Ritualist consume. If you do, draw a card. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Trample
{T}, Sacrifice another creature: You gain 3 life.
Whenever another creature you control dies, put a +1/+1 counter on Bloodbriar Archdruid.

Flying, haste
{1}{R}{R}: Return Bloodfire Phoenix from your graveyard to the battlefield. Activate only if an opponent lost 3 or more life this turn.

Equipped creature gets +1/+1 and has lifelink.
Whenever equipped creature dies, if it wasn't a token, you may pay {3}. If you do, create a token that's a copy of that creature and attach Bloodguard's Hand to it.
Equip {3}

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.

{G}, {T}: Put a +1/+1 counter on Bloodleaf Tracker for each creature that entered the battlefield this turn.

Discard a card: Bloodshot Berserker gets +1/-1 until end of turn. Any player may activate this ability.

Align X (Choose modes with total ★ less than or equal to X. You may choose modes multiple times.)
• ★ — Bloodstained Calamity deals 1 damage to each creature, player, and planeswalker.
• ★★ — Return target instant or sorcery card from your graveyard to your hand. Exile Bloodstained Calamity.
• ★★★★★ — Bloodstained Calamity deals 10 damage to any target.

Bloodstone Halls enters the battlefield tapped unless you control two or more black and/or red permanents.
{T}: Add {B} or {R}.

Flying, deathtouch
When Bloodsucking Pihuchen enters the battlefield, choose a nonland card name.
Whenever a permanent with the chosen name enters the battlefield, each opponent loses 1 life and you gain 1 life.

Haste
Bloodvenge Berserker doesn't untap during its controller's untap step.
Once each turn, when an opponent is dealt damage by another source you control, you may untap Bloodvenge Berserker.

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.)

When Blossoming Expanse enters, you may put a basic land card from your hand onto the battlefield tapped.
{1}, {T}: Add one mana of any color.

For each Aura you control, create a token that's a copy of that Aura.

Trample
{T}: Add {C}.
At the beginning of your upkeep, you may pay {2}. When you do, Blundering Clocktower becomes a creature in addition to its other types until the beginning of your next end step. End the turn.