msem-instigator

Basin Fortress enters tapped unless you control a basic land.
{T}: Add {B} or {G}.

{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.)

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

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

Equipped creature has menace and trample.
Equip {2}

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

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.)

When Big Rock enters, it deals 2 damage to any target.
{T}: Add {C}.
{T}, Sacrifice Big Rock: It deals 2 damage to any target. Activate this ability only if you control a Giant.

Bigroot Valley enters 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, 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, 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.

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

When Blackwall's Edge enters, 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.

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 tapped.

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

Bleakrealm Moor enters tapped unless you played it from exile.
{T}: Add {B} or {R}.

({T}: Add {W} or {B}.)
As Blessed Mausoleum enters, you may pay {1}. If you don't, Blessed Mausoleum enters tapped.