msem-instigator

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast enchantment spells or to activate an ability of an enchantment.
When Bastion, Node of the Free is destroyed, return it to its owner's hand.

Equipped creature gets +1/+1.
As long as equipped creature is a Soldier or Warrior, it gets an additional +1/+1.
Equip {1}

{4}{G}: Battle Station gets +3/+3 until end of turn.
Cycling {2/G} ({2/G}, Discard this card: Draw a card.)

At the beginning of your upkeep, Bauble of Infinites deals 2 damage to each opponent and you gain 2 life.

(Transform this if it's not attached to a creature. Pay {1}{U} as a sorcery to unattach it.)
Enchant creature you control
Bay-Bandit's Snapper's rider gets +1/+2.
Whenever Bay-Bandit's Snapper's rider deals combat damage to a player, you draw two cards.

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

Equipped creature has menace and trample.
Equip {2}

Whenever you cast an instant or sorcery spell, each opponent loses 1 life and Beast of Pestilence 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.

(Transform this if it's not attached to a creature. Pay {2}{B}{B} as a sorcery to unattach it.)
Enchant creature you control
Belmord Blood-Coach's rider gets +3/+3 and has deathtouch.
Whenever Belmord Blood-Coach's rider attacks, you may return target creature card with mana value less than its rider's power from your graveyard to the battlefield tapped.

Whenever equipped creature attacks, it gets +X/+0 until end of turn, where X is its power.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Enchant creature
At the beginning of the upkeep of enchanted creature's controller, Betrayer's Mantle deals 3 damage to that player.

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

Equipped creature gets +1/+1.
Whenever equipped creature becomes blocked, you may pay {1}{W}. If you do, detain each creature blocking it. (Until your next turn, those creatures can't attack or block and its activated abilities can't be activated.)
Equip {2}

When Bio-Sequencer enters the battlefield, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
{1}, {T}, Sacrifice Bio-Sequencer: Add one mana of any color.

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 Blackwall's Edge enters the battlefield, if you control four or more lands, you may have each player conjure a card named Data-Point into their hand. (It's a sorcery that costs {2} with “Draw a card.”)
{T}: Add {C}.
When Blackwall's Edge is destroyed, return it to its owner's hand.

At the beginning of your upkeep, if Blade of Ancestors isn't attached to a creature, create a 1/1 white Soldier creature token, then attach Blade of Ancestors to it.
Equipped creature gets +1/+1.
Equip {2}

Equipped creature gets +3/+1.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Blade of the Many can be attached only to a nonlegendary creature.
Equipped creature gets +2/+2.
Each other creature you own is a copy of equipped creature.
Effects that would cause permanents you own to become creatures cause them to become copies of equipped creature instead.
Equip {6}

Equipped creature gets +2/+0.
Equip {1}

If a player would mill one or more cards, they mill that many cards plus two instead.

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

Bleak Shoreline enters the battlefield tapped unless you control an Island.
{T}: Add {W} or {B}.