msem-instigator

When a creature you control becomes the target of a spell or ability an opponent controls, sacrifice Bestial Harmony. If you do, draw three cards.

Bestial Mob's power and toughness are each equal to the number of creatures you control.
Whenever Bestial Mob deals combat damage to a player, destroy target creature with toughness less than Bestial Mob's power.

When Bestower of Blooms dies, create an X/X green Plant Knight creature token, where X is Bestower of Blooms's power.

{T}, Exert Bestower of Princely Sin: You may sacrifice another creature. If you do, target opponent may sacrifice a permanent that shares a card type with it. If they don't, that player loses 1 life and you draw a card. Repeat this process for artifact, enchantment, land, and planeswalker. Activate only as a sorcery.

Enchant Equipment
You control enchanted Equipment.

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

You may have Better Half enter as a copy of any creature on the battlefield, except it's a Reflection in addition to its other creature types and it has distorted. (It can be blocked by tapped creatures but not untapped creatures.)

Enchant two nonland permanents you control
Once each turn, when you activate an ability of one of the enchanted permanents, you may put a +1/+1 counter, a loyalty counter, or a charge counter on each enchanted permanent. (They can be different counters.)

When Beyond the Boneyard enters, exile another target nonland permanent until Beyond the Boneyard leaves the battlefield.
Your opponents can't cast spells that share a card type with the exiled card during postcombat main phases.

When Beyond the Veil enters, if it was cast, another target nonland permanent phases out. (Treat it and anything attached to it as though they don't exist.)
Nonland permanents you don't control with mana value 3 or less can't phase in.

When Bezoarbeast dies, each opponent loses 2 life and you create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Enchant creature
Converge — When Big Enough enters, put X +1/+1 counters on enchanted creature, where X is number of colors of mana spent to cast Big Enough.
Enchanted creature has trample.

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.

Trample, haste, indestructible
Whenever a permanent an opponent controls is put into a graveyard from the battlefield, put a +1/+1 counter on target Ooze.

Whenever you cast a noncreature spell, target player mills two cards.
{U}: This creature gets +1/-1 until end of turn.

(Add a quest counter as this enters. Sacrifice after 4.)
Whenever a creature you control enters, add a quest counter.
1 — Exile target nonland permanent an opponent controls until target creature you control leaves the battlefield.
2, 3 — Each player may scry 1.
4 — Put all cards exiled with Bind the Great Evil into their owners' graveyards.

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

Enchant creature
Enchanted creature can't attack or block alone.

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}

Flash
When Binding Stones enters, exile target creature with power 3 or less until Binding Stones leaves the battlefield.

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.

{T}: Add one mana of any color a basic land you control could produce.

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.