msem-instigator

Equipped creature gets +1/+0 and gains “Whenever this creature deals damage to a player or planeswalker, you may draw two cards. If you do, discard a card.”
Equip {2}

Create two 2/2 white Griffin creature tokens with flying. If you control a legendary creature, create three of those tokens instead.

({T}: Add {G} or {W}.)
Sungrace Meadows enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sunken Cavern enters tapped unless another player controls a land that could produce {U} or {R}.
{T}: Add {U} or {R}.

Pressure {3}{B}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
When Sunken-Eye Angler enters, mill three cards. Then if it was cast for its pressure cost, you may return a creature card from your graveyard to the battlefield.

Lifelink
When Sunlight Dancer enters, target opponent gains 4 life.

({T}: Add {G} or {W}.)
As Sunlit Plaza enters, you may pay {1}. If you don't, Sunlit Plaza enters tapped.

Sunny Dunes enters tapped unless another player controls a land that could produce {R} or {W}.
{T}: Add {R} or {W}.

Hexproof
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
As long as Sunrise Sentinel is renowned, other Scouts you control have hexproof.

Sunspear Surge deals 2 damage to target creature and 1 damage to each other creature.

When Sunwright Scion enters, put a +1/+1 counter on each other creature you control.
At the beginning of each combat, you may have target creature with a +1/+1 counter on it gain your choice of vigilance, lifelink, or trample until end of turn.

Each creature with a law counter on it can't attack or block.
{2}{W}, {T}: Remove all law counters from all permanents, then put a law counter on target creature.

When Suraj Militant enters, target creature gets +1/+1 until end of turn.

Target creature gets +X/+X until end of turn.
Fabled {X}{R}{R} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Surging Lightning deals 2 damage to target creature or planeswalker. If you've cast another spell this turn, it deals 4 damage instead.

Submerge up to two target attacking nontoken creatures an opponent controls. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

You may have Surging Wurm assign its combat damage as though it weren't blocked.
Surging Wurm gets +2/+2 as long as seven or more cards are in your graveyard.

Target creature gains double strike and trample until end of turn. (Then exile this card. You may cast the creature later from exile.)

Flash
When Surreal Bakhtak enters, choose one —
• Destroy target tapped creature.
• Tap up to three target creatures.

Flying, prowess
Whenever Surveyor of Skies attacks, you may return a permanent you control to its owner's hand.

Wanderlust — When you cast this spell, you may copy it if you control four or more differently named lands. You may choose new targets for the copy.
Untap target creature you control. It gets +1/+1 and gains hexproof and indestructible until end of turn.

As an additional cost to cast this spell, discard a card.
Return up to one target instant card and up to one target sorcery card from your graveyard to your hand. Exile Sustaining Meditation.

Swarm of Sporemites gets +1/+1 for each creature card and Revelation card in your graveyard.

Target creature deals damage equal to its power to its controller.

{T}: Add {C}.
{T}, Pay 1 life: Add {W}.
{5}{W}, {T}, Sacrifice Swaying Sands: Create three 1/1 white Bird creature tokens with flying. Activate only as a sorcery.