msem-instigator

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Settling of Nizev enters, look at the top four cards of an
opponent's library, exile two of them, and put the rest on the bottom of their library in a random order. You may play those cards for as long as they remain exiled, and mana of any type can be spent to cast them.opponent's library, exile two of them, and put the rest on the bottom of their library in a random order. You may play those cards for as long as they remain exiled, and mana of any type can be spent to cast them.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Settling of Soli enters, reveal the top four cards of your library. You may put a noncreature card from among them into your hand. Put the rest on the bottom of your library in any order.

When Seven Deadly Sins has seven or more sin counters on it, sacrifice it.
{B}{B}, Put a sin counter on Seven Deadly Sins: Destroy target creature. This ability costs {1} more to activate for each sin counter on Seven Deadly Sins.

Flash
Menagerie — When Seven Seas Scourge enters, if there are five or more creature types among creatures you control, counter target spell with mana value 4 or less.

Whenever equipped creature deals combat damage to a player, return to your hand all cards from your graveyard that were put there this turn.
Equip {3}

Flash

Once each turn, when another creature you control enters, you may search your library for a card with the same name as that creature, reveal it, put it into your hand, then shuffle.

At the beginning of your upkeep, you may pay {B}. If you do, return a Wizard card from your graveyard to your hand.

Whenever an artifact is put into your graveyard from the battlefield, you may draw a card. If you do, discard a card.
{T}, Exile three noncreature cards from your graveyard: Create a 1/1 colorless Construct artifact creature token.

[+1]: Create a 1/1 green Scout creature token. If you control six or more lands, also create a 1/1 white Bird creature token with flying.
[–1]: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.
[–5]: You get an emblem with “Whenever each permanent you control becomes tapped for the first time each turn, untap it.”

When Sewer Dweller enters or dies, create a 1/1 black Rat creature token with “This creature can't block.”

As long as Sewer Pack is on the battlefield, you may cast spells named Sewer Pack from your graveyard.
Sewer Pack gets +1/+1 for each other creature on the battlefield named Sewer Pack.

Flying
When Sha Long enters, each player chooses an artifact they control, then sacrifices the rest. If they don't control an artifact, they may return an artifact card from their graveyard to the battlefield. Repeat this process for creatures, enchantments, and planeswalkers.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Ward {2}
{2}{U}: Demigod — Exchange a card in your hand and a noncreature, nonland card in your graveyard.
{6}{U}: God — Exchange control of two target permanents that share a card type.

When Sha'Iv Cagemage enters, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Whenever an Aura you control enters, you may tap target creature.

Vigilance
Sha'Iv's Emissary gets +1/+1 as long as you control a blue or red permanent.

When Sha'Iv's Scout enters, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Whenever an Aura you control enters, target creature can't block this turn.

{U}{R}{W}, Discard a card named Sha'Iv, God of Order: Sha'Iv gains indestructible and becomes a God creature in addition to its other types.
Whenever Sha'Iv enters or attacks, choose target creature an opponent controls. Untap it, then tap each other creature that player controls. They don't untap during their controller's next untap step.

I, II — Whenever a creature you control attacks alone this turn, put a +1/+1 counter on it.
III — Whenever a creature you control attacks alone this turn, it gains double strike and lifelink until end of turn.

At the beginning of your upkeep, you lose 1 life.

Shadow Courier can't be blocked.

Enchant creature
When Shadow Infestation enters, enchanted creature's controller loses 2 life.
Enchanted creature gets -1/-1 and can't block.

Your opponents play with their hands revealed.

(Activate each submodule once as a sorcery. When this enters, activate one submodule for free.)
{2}{U}: Imitate
Choose any number of target cards in graveyards. Their owners shuffle them into their libraries. Then you draw a card.
{2}{B}: Deceive
Surveil 5.
{1}{U}{B}: Obfuscate
Shadow Module gains “At the beginning of your upkeep, if there are four or more card types among cards in your graveyard, you may draw a card.”

Flash
When Shadow Stalker enters, for each player, look at the top card of that player's library. You may have that player put that card into their graveyard.