msem-instigator

Flying
When Silent Griffin enters, draw three cards, then put two cards from your hand on top of your library.

Silent Hunt deals 3 damage to target creature and you gain 3 life.
Forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

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.

Target opponent exiles cards from the top of their library until X land cards are exiled, where X is the number of land cards in your graveyard.

Return target creature to its owner's hand. If you controlled that creature, draw a card.

Prevent all combat damage that would be dealt to Silent Reaver.
Prevent all combat damage Silent Reaver would deal to creatures.

Silent Ridge enters tapped.
{T}: Add {B}.
Desertcycling {1}{B} ({1}{B}, Discard this card: Search your library for a Desert card, reveal it, and put it into your hand, then shuffle.)

Return target creature card from your graveyard to your hand.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Non-Avatar creatures can't attack you or planeswalkers you control unless their controller pays {2} for each of those creatures.

Flash
You may cast cryptic spells as though they had flash. (Artifacts, enchantments, and modal spells are cryptic.)

Flash (You may cast this spell any time you could cast an instant.)
When Silk Crane Adept enters, target creature gains hexproof until end of turn.

Reach

Flying, vigilance
When Silksoul Celestial enters, search your library for an enchantment or Aurashaper card, reveal it, put it into your hand, then shuffle.
When Silksoul Celestial dies, you may put an enchantment or Aurashaper card from your hand or graveyard onto the battlefield.

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.

{2}, Pay 2 life: Silkwrap Brawler gains indestructible until end of turn.

{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.

Whenever you discard one or more cards, create a Treasure token and draw a card. This ability triggers only once each turn.
Whenever two or more creatures you control attack, you may discard a card. If you do, target creature can't block this turn.