msem-instigator

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

Inspired — Whenever Bearer of Vile Incense becomes untapped, create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”

Equipped creature has menace and trample.
Equip {2}

Reveal the top three cards of your library. Put all creature cards revealed this way into your hand and the rest into your graveyard.

Desecrate (When this creature enters the battlefield, you may sacrifice an artifact or land.)
When Beastback Raider desecrates a permanent, discard your hand, then draw three cards.

Target creature you control gains indestructible until end of turn if it's embattled. Then it fights target creature you don't control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Look at the top two cards of your library. Put one of them into your hand, then submerge the other. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Concord — When Beetleback Forager enters the battlefield, if there are four or more card types among permanents you control, return target card from your graveyard to your hand.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Target opponent reveals their hand. You choose a nonland permanent card from it. That player discards that card.

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.

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.

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

Exile target nonland permanent. Its controller gains 5 life.

When Beyond the Boneyard enters the battlefield, 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.

Target creature you control becomes a copy of another target creature you control until end of turn.
Showcase {2}{U}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Return target creature card from your graveyard to the battlefield. If it was put there from the battlefield this turn, create a token that's a copy of it. If you're in a renaissance, create a token that's a copy of it.

Desecrate (When this creature enters the battlefield, you may sacrifice an artifact or land.)
When Bitter Wanderer desecrates a permanent, each opponent loses 2 life and you gain 2 life.

Bjarndyr Bruiser gets +2/+2 as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Bjarndyr Mender enters the battlefield, other creatures you control get +1/+1 and gain indestructible until end of turn.

When Bjarndyr Militant enters the battlefield, return target Aura card or card with fabled from your graveyard to your hand.

When Bjarndyr Outfitter enters the battlefield, arm up to two target creatures you control. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Lifelink
Whenever Bjarndyr Sergeant attacks, other creatures you control get +1/+1 and gain lifelink until end of turn.

Trample
Other Bears you control get +2/+2.