msem-instigator

Auras and Equipment you control have indestructible.
Whenever Bearidge Marshall attacks, you may create a white Aura enchantment token named Arrest attached to target creature. It has enchant creature and “Enchanted creature can't attack or block, and its activated abilities can't be activated.”

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Damage can't be prevented this turn. Beat & Batter deals 2 damage to target player, then 2 damage to each player that's gained life this turn.

Sleight (You may cast this spell as though it had flash if you pay {1} more to cast it.)
Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle.

Bloodprice {2}{B}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Return target creature card from your graveyard to your hand. If you cast this spell for its bloodprice, return that card to the battlefield instead.

Draw a card, then reveal any number of creature or land cards from your hand. You gain that much life.

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Other Knights and Soldiers you control get +1/+0.
Cowards can't block Knights and Soldiers you control.
When Belmord Bloodcurdler enters the battlefield, target creature an opponent controls becomes a Coward in addition to its other types.

Mill four cards, then you may return a creature or planeswalker card from your graveyard to your hand.
As long as Beneath the Zhedina is in your graveyard, other cards in your graveyard can't be the target of spells or abilities your opponents control.

Flying
When Benevolent Malach enters the battlefield, create a 1/1 colorless Construct artifact creature token.
Sacrifice Benevolent Malach: Artifacts you control gain indestructible until end of turn.

Flying
Sacrifice six Swamps: Return Berbarus Unsealed from your graveyard to the battlefield with an indestructible counter on it. You draw six cards and you lose 6 life.

When Bessie's Brood enters the battlefield, it fights target creature. (If there are no other creatures, it eats itself.)

[+2]: Create a 3/3 red Wurm creature token.
[–2]: Up to three target creatures each get +2/+2 until end of turn. Bessie deals 2 damage to each of up to three target creatures.
[–9]: You get an emblem with “Creatures you control have base power and toughness 7/7 and have indestructible.”

Create a 3/3 green Beast creature token, then populate. (Create a token that's a copy of a creature token you control.)

Return all creature and planeswalker cards from your graveyard to the battlefield.

Bigroot Valley enters the battlefield tapped.
{T}: Add {R} or {G}.
{1}, {T}: Add one mana of any color.

When Bind the Mind enters the battlefield, each poisoned opponent reveals their hand. Then choose a nonland card name.
Spells with the chosen name can't be cast.

When Bird Call enters the battlefield, search your library for a creature card, reveal it, shuffle, then put that card on top.
{2}, {T}: Target creature gets +1/+1 until end of turn.

When Black Cat dies, target opponent discards a card at random.

You lose 1 life and exile the top card of your library. You may repeat this process any number of times. Then put up to two cards exiled this way into your hand.
Coalesce {5}{B}{B} (You may cast this from your graveyard for its coalesce cost. If you do, put it onto the battlefield as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Black Hole Musings's power is equal to the number of cards in exile.

Menace
When Blackmoat Bully dies, put a +1/+1 counter and a menace counter on target creature you control.

Equipped creature gets +4/+2 and has first strike, vigilance, and trample.
Equip {3}

Advance {1}{R}{W}{B} (Cast this for {1}{R}{W}{B} to advance it as it enters. {1}{R}{W}{B}: Advance this as a sorcery.)
Whenever Blastburn Angel advances, it gets +1/+1 and gains flying until end of turn. It deals 1 damage to each other creature.

Blazing Volley deals 1 damage to each creature your opponents control.

({T}: Add {U}, {B}, or {R}.)
Bleak Dominion enters the battlefield tapped.