msem-instigator

{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.)

Concord — Silt-Trench Brute gets +3/+3 and has trample as long as there are four or more card types among permanents you control.

{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.
Draw cards equal to the number of quest counters on Siltbottom Expedition, then discard that many cards.
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}{U}, {T}: Look at the top card of your library. If it's a Scout card or a card with an Adventure, you may reveal it and draw a card.

{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.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Siltsplitter desecrates a permanent, each opponent sacrifices an artifact.

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.)

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

When Silvercrest Historian enters, scry 1, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Vigilance
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Silvercrest Sentry attacks, untap up to one target legendary creature you control.

When Silverhorn Battlemaster enters, put a +1/+1 counter on up to two target Warriors you control.
Whenever Silverhorn Battlemaster deals combat damage to a player, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

When Silverhorn Tactician enters, permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Adorned — As long as Silverwork Champion is equipped and/or enchanted, it gets +2/+2 and has trample.

Trample
Whenever Simian Sentinel attacks, it gets +X/+0 until end of turn, where X is the number of lore counters on Sagas you control.

First strike

Whenever Simian Striker attacks, it gets +3/+0 until end of turn.

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.)

Destroy target creature. It can't be regenerated.

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.)

Target player reveals a number of cards from their hand equal to the number of creature cards in your graveyard. You choose one of them. That player discards that card.