msem-instigator

Destroy all nonland, nonenchantment permanents.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you gain 2 life for each permanent destroyed this way.

(Transform this if it's not attached to a creature. Pay {3}{B} as a sorcery to unattach it.)
Enchant creature you control
Corrupted Mount's rider gets +5/+4 and can't block.

Splintering Hail deals 5 damage divided as you choose among any number of target blocking creatures.

Destroy target creature. End of the Road deals damage equal to that creature's power to that creature's controller or a planeswalker that player controls.

Target player sacrifices a creature unless they discard a creature card.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

First strike, lifelink
Once each turn, when another nontoken creature you control dies, you may create a 2/2 white Elk Spirit creature token with first strike and lifelink named Fawn of Hesediel.

Target player discards two cards.

(Activate each submodule once as a sorcery. When this enters, activate one submodule for free.)
{4}{U}: Thinking
Conjure three cards named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
{4}{R}: Dreaming
Discard any number of cards, then draw that many cards and add that much {R}.
{3}{U}{R}: Feeling
Imagination Module gains “Whenever you discard a card, exile the top card of your library. You may play it until the end of your next turn.”

Death knell — Each opponent loses 1 life. You gain life equal to the amount of life lost this way. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Whenever a creature dies, trigger a death knell of a permanent you control.

Creatures you control get +2/+2 and gain vigilance and trample until end of turn.

Target player sacrifices any number of lands. That player searches their library for up to that many land cards, puts them onto the battlefield tapped, then shuffles.
Fabled {5}{G}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

You draw X cards and you lose X life, where X is the number of different names among land cards in your graveyard.

Flying, ward {2}
Whenever Realm Crossers deals combat damage to a player, create a blue enchantment token named Tambo with “At the beginning of your upkeep, draw a card if you control a Scout.”

Whenever Scavenger of the Old Bay deals combat damage to a player, draw a card.
Ride {1}{U} ({1}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Vigilance, deathtouch, menace

Reach

When Realmwalker Domovoi enters, exile another target permanent you control. Return it to the battlefield under your control at the beginning of the next end step.

Rapport — Whenever Memorial of Forgotten Heroes and at least one other creature you control become tapped, put a +1/+1 counter on one of those creatures.
{T}, Tap an untapped creature you control: Add one mana of any color.

Discard a card, then return up to two creature cards from your graveyard to your hand.

{3}{U}, Exile a card from your graveyard: Omen Serpent can't be blocked this turn.

The “legend rule” doesn't apply to artifacts and enchantments you control.
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

{T}: You gain 1 life.
{1}{W}, {T}: Tap or untap another target creature.

At the beginning of each player's end step, that player chooses from among nonland permanents they control an artifact, a creature, an enchantment, and a planeswalker, then sacrifices the rest.

Put target creature or planeswalker into its owner's library third from the top. Its controller creates a 1/1 white Spirit creature token with flying.

When Tempered Ankulim enters, choose one —
• You gain 2 life.
• Each opponent loses 2 life.