msem-instigator

Menace
Whenever Auros, Flame-Cursed attacks, it deals 3 damage to each opponent.

({T}: Add {R} or {G}.)
Autumn Canopy enters the battlefield tapped.
{1}, {T}: Add {R}{R} or {G}{G}.

{T}: Add {C}.
{2}, {T}: Add three mana of any one color.

Autumnal Boscage enters the battlefield tapped unless you control a basic land.
{T}: Add {R} or {G}.

{T}: Add {C}.
Satrapies you control have “{1}{R}, {T}, Discard a card: Draw a card.”

Avaz Sanctuary enters the battlefield tapped.
Satrapies you control have “{T}: Add {R} or {W}.”

Avaz Temple enters the battlefield tapped.
Satrapies you control have “{T}: Add {R} or {G}.”

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Backstage Rooms: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Indestructible
You may play cards from your graveyard.
If you would draw one or more cards, mill that many cards instead.
If a card would be put into your graveyard from anywhere other than your library, exile it instead.

Vigilance, deathtouch
Whenever a creature dealt damage by Barbed Bruiser this turn dies, draw a card.

Barbed Reef enters the battlefield tapped. When it does, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this, then you may mill that card.)
{T}: Add {B}.
{4}{B}: Barbed Reef becomes a Jellyfish creature. (This effect lasts indefinitely.)

Barren Boneyard enters the battlefield tapped.
{T}: Add {B}.
{2/B}{2/B}: Barren Boneyard becomes a 2/3 black Elemental creature with deathtouch until end of turn. It's still a land.

As Barren Desolation enters the battlefield, you may pay 2 life. If you don't, Barren Desolation enters the battlefield tapped.
{T}, Sacrifice Barren Desolation: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Barren Vista enters the battlefield tapped.
{T}: Add {U} or {B}.
{1}, {T}: Add one mana of any color.

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

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.

(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.

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.

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}

({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}.

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