msem-instigator

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When Skypath Pilgrimage enters, journey twice. (Exile the top two cards of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Skysovereign Griffin attacks, it gets +1/+0 until end of turn for each other attacking creature with flying you control.

Flying
Whenever an embattled creature you control deals combat damage to a player, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Whenever Skysworn Savior attacks, you may return another creature you control to its owner's hand. If you do, Skysworn Savior gets +2/+2 and gains flying until end of turn.

Enchant creature
Enchanted creature gets +1/+1.
Whenever enchanted creature deals damage to a player or planeswalker, draw a card.

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

Flying
As long as you control exactly one other creature, that creature gets +1/+1 and has flying.

Slay Them in the Aisles deals 2 damage to each non-Actor creature.

Target creature blocks this turn if able. You may have it gain reach until end of turn.
Draw a card.

Whenever Sledgesuit Prospector attacks, choose any number —
• Sacrifice an artifact. If you do, put a +1/+1 counter on Sledgesuit Prospector.
• Discard a card. If you do, create a Treasure token.

Return target instant or sorcery card from your graveyard to your hand.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Prowess
Whenever you cast a noncreature spell, you may mill two cards.

Flying, vigilance

Identity — As long as you control at least two other creatures that share a creature type with Slicing Steer, Slicing Steer and creatures you control that share a creature type with it get +1/+0 and have menace.

Flying
When Slighted Spirit enters, detain up to two target creatures. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Target player puts the bottom X cards of their library into their graveyard.

Equipped creature has “{1}, {T}: This creature deals 1 damage to any target.”
Whenever equipped creature deals damage to a creature with power 5 or greater, sacrifice Sling of the Meek. If you do, destroy that creature.
Equip {3}

Creatures your opponents control get -4/-0 until end of turn.
Quickdraw {1}{U}{U} (When a creature you control blocks or becomes blocked, you may cast this spell for {1}{U}{U}.)

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.

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

(Add a quest counter as this enters. Sacrifice after 3.)
Once each turn, when you cast an instant or sorcery spell, you may add a quest counter.
Slipsand Expedition deals damage equal to the number of quest counters on it to any target.
Add {R}{R}{R}.

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

{1}, {T}: Surveil 2.
{U}, {T}, Discard a card: Look at the top card of your library. If it's a nonland card, you may cast it. (You still pay its costs)

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.