msem-instigator

Return target nonland permanent to its owner's hand.
Inscribed creature gets +1/+1 and has flying.
Inscribe {3}{U} ({3}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Shrouded Cackler can't block.

Shu Qin enters with your choice of a flying or +1/+1 counter on him.
At the beginning of your upkeep, choose a creature in Shu Qin's pack. He gains that creature's abilities until end of turn. (Two or more creatures you control with equal power are in a pack.)

Vigilance
Whenever Sibling of All Elements attacks, it gains flying until end of turn if you control a creature with flying. The same is true for first strike, double strike, deathtouch, indestructible, lifelink, menace, and trample.

When Sift Through False Leads enters, exile the top five cards of your library, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{2}, Sacrifice a Clue: Put a card exiled with Sift Through False Leads into your hand.

Prowess
{T}: Catalyze, then catalyze again. Activate only if Sigil Slinger's power is 5 or greater. (The next spell you cast this turn costs {2} less to cast.)

Creature tokens you control get +1/+0.

Equipped creature has “{T}: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.”
Equip {2}

{T}: Scry 1.

When Silence Dissent enters, each player exiles a card from their hand at random until Silence Dissent leaves the battlefield.
{1}{W}: Exile Silence Dissent. Return it to the battlefield under your control at the beginning of your next end step.

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.

Silent Doom enters tapped.
You may cast Silent Doom from your graveyard as long as you sacrificed a permanent this turn.
Cycling {B} ({B}, Discard this card: Draw a card.)

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.”)

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.)

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.)

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.

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.)

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