msem-instigator

When Bayou Courier enters, you may pay 2 life. If you do, create a 3/2 green Crocodile creature token with trample.

Concord — When Bazaar Equestrian enters, if there are four or more card types among permanents you control, you gain 4 life.

Flash
Haste
{3}, {T}: Exchange control of two target noncreature spells. Their controllers may choose new targets for the spells.

Whenever Bazaar Informant deals combat damage to a player, reveal the top card of that player's library. If it's a nonland card, put a +1/+1 counter on Bazaar Informant, then that player puts that card into their graveyard.

If you would catalyze, catalyze twice instead. (The next spell you cast this turn costs {1} less to cast.)
You may pay an additional {2} as you cast a spell. If you do, reveal the bottom card of your library. You may put it into your graveyard or on top of your library.

Beachhead Partisan has first strike as long as it's attacking.
When Beachhead Partisan enters, it deals X damage to any target, where X is the number of tapped creatures you control.

Enchant creature
Enchanted creature has base power and toughness 8/8.

When Bearer of Old Growth enters, choose one —
• Untap up to two target artifacts.
• Draw a card.

When Bearer of Silk Chains enters, gain control of target nonland permanent until Bearer of Silk Chains leaves the battlefield. If that permanent is a Horror, gain control of it instead.

Inspired — Whenever Bearer of Vile Incense becomes untapped, create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”

When Bearer of the Lantern enters, you gain 3 life.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Whenever an artifact or enchantment you control enters, you may detain target nonland permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Whenever you detain a permanent, you gain life equal to that permanent's mana value.

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.”

Reveal the top three cards of your library. Put all creature cards revealed this way into your hand and the rest into your graveyard.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Beastback Raider desecrates a permanent, discard your hand, then draw three cards.

Menace
When Beatrice enters, target opponent reveals their hand. Exile a nonland card from it. During any turn that player lost life, you may cast that card and mana of any type can be spent to cast that spell.

Look at the top two cards of your library. Put one of them into your hand, then submerge the other. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Return up to one target creature card and up to one target noncreature permanent card with total mana value 4 or less from your graveyard to the battlefield.
Exile Beckon the Damned.

Draw a card, then create a 1/1 blue Elemental creature token. If you drew three or more cards this turn, create three of those tokens instead.

Whenever you cast an enchantment spell, you draw a card and you lose 1 life.
Whenever one or more counters are put on an enchantment you control, you gain 1 life and each opponent loses 1 life.

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

If you control ten or more nonland permanents, you get an emblem with “At the beginning of your end step, return target permanent card from your graveyard to the battlefield.”
Destroy all nonland permanents.

Bedfellow can't block or be blocked.
Exile two cards from your graveyard: Bedfellow gets +1/+1 until end of turn.

{T}: Add one mana of any color.
{2}, {T}: Put a lore counter on a Saga you control.