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 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.

Destroy target token.

For each player, exile target creature or planeswalker they control.

As an additional cost to cast this spell, discard a card or pay {4}.
Destroy target creature.

Destroy target creature. If an opponent lost life this turn, that creature's controller mills five cards.

Destroy target creature or planeswalker. If you controlled a black legendary creature or planeswalker as you cast this spell, that permanent's controller loses X life and you gain X life, where X is that permanent's mana value.

When Severed Hands enters, surveil 2.
Whenever one or more cards leave your graveyard, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

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.”

Exile two target cards from your graveyard. If they share a card type, draw a card. (Then exile this card. You may cast the creature later from exile.)

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.

Create three 0/0 colorless Reflection creature tokens. Creature tokens you control get +2/+2 until end of turn.