msem-instigator

Mill three cards, then counter target spell unless its controller pays {X}, where X is the greatest mana value among cards milled this way.

You gain hexproof until end of turn.
Prevent all damage that would be dealt to you this turn.

As Silent Hypnotist enters, choose a noncreature card name.
Spells with the chosen name can't be cast.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

When Silkweaver Matron enters, create a white Aura enchantment token named Spinning Silk attached to target creature. The token has enchant creature and “Whenever enchanted creature attacks, tap target creature defending player controls.”
{1}{W}: Untap target enchanted creature.

{T}: Add {C}.

Whenever Silt Lurker deals combat damage to a player, mill three cards, then draw a card if seven or more cards are in your graveyard.
Cycling {G} ({G}, Discard this card: Draw a card.)

When Silt Miner enters, you may salvage an artifact or creature card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

{T}: Untap another target nonland permanent. Activate only as a sorcery.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you cast your first spell outside your main phase each turn, add a quest counter.
1, 2 — Draw cards equal to the number of quest counters on Siltbottom Expedition, then discard that many cards.
3 — Put up to two target instant or sorcery cards from your graveyard on top of your library in any order, then draw a card.

Whenever Siltbottom Freebooters attacks, target Pirate gains menace until end of turn.

{2}{B/G}: Return Silthway Scuttler from your graveyard to your hand.
{2}{B/G}, Exile Silthway Scuttler from your graveyard: Put two +1/+1 counters on target creature.

When Silver Gardener enters, create a 1/1 green Saproling creature token.
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

Silver-Dawn Elder gets +2/+2 as long as you control five or more lands.
Revive—{2}{G}{G}, Discard a card. ({2}{G}{G}, Discard a card, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Menace
Whenever Silver-Dawn Radiant becomes the target of a spell or ability you don't control, it deals damage equal to its power to that spell or ability's controller.

Whenever you draw a card, Silverblood Aspirant gets +1/+1 until end of turn.
{1}{R}, Discard a card: Draw a card.

When Silvercrest Vanguard enters, scry 1, then draw a card.
Whenever you draw your second card each turn, put a +1/+1 counter on Silvercrest Vanguard.

As long as you are glorious, you may look at the top card of your library. (You are glorious as long as you have a glory counter.)

Whenever you pay a tithe, you may pay {2}. If you do, each opponent loses 3 life and you gain 3 life.

Target player sacrifices a creature.
Fabled {2}{B} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Whenever Single-Minded Mob becomes untapped, it gets +2/+2 until end of turn.

Each creature gets -X/-X until end of turn. Destroy each artifact and enchantment with mana value X or less.

Choose one —
• Target creature gets +1/+1 and gains lifelink until end of turn.
• Target creature gets -2/-2 until end of turn.
• Scry 1, then draw a card.

Whenever a storied permanent you control enters, each opponent loses 1 life and you gain 1 life. (Enchantments and legendary permanents are storied.)
{2}{B}{B}, Sacrifice Sinister Heir: Return target storied card from your graveyard to the battlefield.

Pay any amount of life. Look at twice that many cards from the top of your library and put one into your hand. Exile the rest.

Equipped creature gets +1/+0 and has menace.
Equip {2}