msem-instigator

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.

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}

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

(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}.

Menagerie — {1}{G}: Slipsand Hornshell gains indestructible until end of turn. Tap it. Activate only if there are five or more creature types among creatures you control.

Slipsand Oasis enters tapped unless you played it from exile.
{T}: Add {W} or {B}.

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

Slipstream Horizon enters tapped.
{T}: Add {U} or {R}.
{U}{R}, {T}, Sacrifice Slipstream Horizon: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

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.

First strike
{2}{R}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)

{T}: Add {C}.
{4}, {T}, Sacrifice Slyten Crystal Motherlode: Add {W}{U}{B}{R}{G}.

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

Whenever Slyten Jewel Runner attacks, target creature can't block until end of turn.
Augmented — At the beginning of your end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Slyten Jewel Runner.

Choose target creature you don't control. When that creature dies this turn, draw a card. Target creature you control fights that creature.

When Smashing Brute enters, target nonbasic permanent loses all abilities until your next turn.
Foresight — Whenever you draw your second card each turn, you may exile Smashing Brute. If you do, return it to the battlefield.

Target creature gets +3/+3 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Smelting Breath deals 5 damage to target creature. Destroy up to one Equipment attached to that creature.

Target creature can't block this turn. Smokescreen deals 2 damage to that creature's controller.

Whenever equipped creature attacks, it gets +3/+3 until end of turn.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Equipped creature gets +2/+1.
Whenever equipped creature blocks or becomes blocked by a creature, it deals 2 damage to that creature.
Equip {2}

Defender
{T}: Smoldering Djinni deals 1 damage to each opponent.
Whenever you cast a red spell, untap Smoldering Djinni.

When Smoldering Husk dies, it deals 2 damage to any target.
{2}{R}: Smoldering Husk gets +2/+0 until end of turn.

Destroy target artifact. Smoldering Pages deals damage to that artifact's controller equal to that artifact's mana value.

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.