msem-instigator

Flying
Whenever Skhorvall Patrol deals combat damage to a player, look at the top card of that player's library.

When Skhorvall Raider enters, if you control an embattled creature, Skhorvall Raider deals 2 damage to any target. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Skittering Atrocity enters, up to one target creature gets -X/-X until end of turn, where X is the number of Horrors you control.

{3}{W}: Tap target creature with power 4 or greater.

Creatures with power less than Skull-Crowned Chief's power can't block.

Flying
When Skymount Reinforcements enters, put a +1/+1 counter on another target creature.

Flying
When Skystream Mantas is returned to your hand from the battlefield, draw two cards.

Rhapsody {3}{W}{W} (Pay {3}{W}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Players can't search libraries unless they pay {X}, where X is Skytouch Distorter's power.

Flying
At the beginning of your upkeep, sacrifice Skyward Dreamers unless you remove a counter from a permanent you control.

Improve {1}{B/R} ({1}{B/R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of each player's combat, you may have that player create two goaded 1/1 red Goblin creature tokens with haste. Exile those tokens at end of combat. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Deathtouch, menace
Slayer of the Famed must be blocked each combat if able.

Ward {2}
Slippery Bunyip can't be blocked except by creatures with Adventures.

Slippery Capuchin can't be blocked.
Whenever Slippery Capuchin becomes the target of a spell or ability, you may change the target of that spell or ability.

{1}{R}: Target creature can't block Slippery Salamander this turn.

Whenever you cast an instant, sorcery, or Wizard spell, Slipsand Runemage deals 1 damage to any target.

As long as there are four or more card types among cards in your graveyard, Slipstream Silencer can't be blocked.
Whenever Slipstream Silencer attacks, surveil 1.

Whenever Slithering Eyes deals damage to a player, you may exile that many cards from the top of your library. Until the end of your next turn, you may play those cards.

Advance {5}{B}{B} (Cast this for {5}{B}{B} to advance it as it enters. {5}{B}{B}: Advance this as a sorcery.)
Whenever Sluiceway Collector advances, put a permanent card from a graveyard onto the battlefield under your control.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
{2}{B}, Sacrifice Sluiceway Shrieker: Put the bottom card of your library into your hand.

When Slyten Analyst enters, you may search your library for a card, then shuffle and put that card on top. If you do, you lose 2 life.

Flying
{R}: Slyten Ignitor gets +1/+0 until end of turn.

When Smokeweaver Initiate dies, draw a card.

Whenever you discard an instant or sorcery card, you may cast it from your graveyard. (You still pay its costs.)
Spells you cast from anywhere other than your hand cost {1} less to cast.

Prowess
When Snowline Ascetic enters, you may put target instant or sorcery card from your graveyard on top of your library.

When Sofia's Swashbucklers enters, you may return target card with foretell from your graveyard to your hand.