msem-instigator

Elemental Envelopment enters with X +1/+1 counters on it.
When Elemental Envelopment enters, if you controlled a green legendary creature or planeswalker as you cast it, search your library for any number of Elemental creature cards with total mana value X or less, where X is Elemental Envelopment's power, put them onto the battlefield, then shuffle.

(Activate each submodule once as a sorcery. When this enters, activate one submodule for free.)
{3}{R}: Rage
The first instant or sorcery spell you cast during your next turn costs {3} less to cast.
{3}{G}: Rampage
The first permanent spell you cast during your next turn costs {3} less to cast.
{2}{R}{G}: Ruin
Fury Module gains “Whenever you cast a spell with mana value 5 or greater, you may draw a card.”

Flying
When Shilgengar's Harvester enters, each opponent discards a card and loses 2 life.

At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard and pay {2}. If the player doesn't, creatures they control can't attack you or planeswalkers you control this turn.

{B}, {T}, Discard a card: Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Assault {B} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Hilaback Outriders assaults, it gains menace until end of turn.

When Frontier Scouts enters, reveal the top card of your library. If it's a land, put it onto the battlefield tapped.

Deathtouch
When Ghastly Scorpion dies, you draw a card and you lose 1 life.

Haste
Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Whenever Goblin War Chariot becomes crewed, untap each creature that crewed it with mana value 1 or less. This ability triggers only once each turn.
Crew 3

Equipped creature gets +2/+0. As long as it's a Knight, it has first strike.
Equip {1}{W}

{2}{G}{G}, Sacrifice a creature: You gain life equal to the sacrificed creature's power or toughness, whichever is greater. Then draw cards equal to the sacrificed creature's power or toughness, whichever is lower. (If the sacrificed creature's power and toughness are equal, the amount of life you gain and cards you draw is equal.)

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Trample, haste
When Blazing Fox enters, you may tap an untapped creature you control. If you do, Blazing Fox gets +X/+0 until end of turn, where X is that creature's power.

Flying, haste
Whenever Shimmering Dragon attacks, for each creature you control, create a tapped and attacking token that's a copy of that creature. Exile the tokens at the beginning of the end step.

Mill three cards. Pyromancer's Fury deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Flying
Whenever you gain life, each opponent loses 1 life.

Kuyen, Moon Spirit can't attack or block unless there are ten or more cards in your graveyard.
At the beginning of each opponent's end step, create two Food tokens. Then you may pay 3 life. If you do, surveil 3, then draw two cards.
When Kuyen dies or is put into exile from the battlefield, you may put her into her owner's library third from the top.

Flying
Whenever an opponent discards a card, put a +1/+1 counter on Nightbane Specter.
Whenever Nightbane Specter deals combat damage to a player, that player discards a card.

Flying
{2/B}{2/B}, {T}, Sacrifice Meddling Gargoyle: Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. Activate only as a sorcery.

Enchant player
At the beginning of enchanted player's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Prowess

Whenever another creature you control dies, put a +1/+1 counter on Marshy Marauder.
When Marshy Marauder dies, create a 1/1 green Insect creature token for each counter on it.

Whenever Skeigr, Skhorvall Flagship attacks, it deals 3 damage divided as you choose among one, two, or three targets.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Flying, deathtouch
{2}{B}{B}, Exile Weku, Malignity Spirit from your graveyard with four pact counters on him: You draw four cards and you gain 4 life.
At the beginning of your upkeep, if Weku is exiled with a pact counter on him, remove a pact counter from him. Then if Weku has no pact counters on him, you lose the game.

Transformed creatures you control get +2/+2.