msem-instigator

Flying
Sacrifice six Swamps: Return Berbarus Unsealed from your graveyard to the battlefield with an indestructible counter on it. You draw six cards and you lose 6 life.

Prevent all combat damage that would be dealt to and dealt by Bereaved Aristocrat.
Unveil {2}{W}{U} ({2}{W}{U}: Transform this. Unveil only as a sorcery.)

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.)

At the beginning of your upkeep, mill a card.
Whenever a creature card is put into your graveyard from anywhere, if that card has flying, you may put a flying counter on Berylscale Alaj. Repeat this process for first strike, double strike, deathtouch, hexproof, lifelink, menace, reach, trample, and vigilance.

{1}{G}: Until your next turn, Bessie becomes a 5/5 green Wurm creature with trample, haste, and indestructible. You can't activate this ability while Bessie is being attacked. (She doesn't lose loyalty while she's not a planeswalker.)
[+1]: Creatures you control get +1/+1 and gain haste until your next turn.
[–6]: Create five 3/3 green Wurm creature tokens with trample and haste.

When Bessie's Brood enters, it fights target creature. (If there are no other creatures, it eats itself.)

Trample
Bessie's Crusher has haste as long as you control another Wurm.

[+2]: Create a 3/3 red Wurm creature token.
[–2]: Up to three target creatures each get +2/+2 until end of turn. Bessie deals 2 damage to each of up to three target creatures.
[–9]: You get an emblem with “Creatures you control have base power and toughness 7/7 and have indestructible.”

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, another target nonland permanent phases out. (Treat it and anything attached to it as though they don't exist.)
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.

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