msem-instigator

First strike
When Soulstone Commander enters, return target Soldier creature card from your graveyard to the battlefield. That creature is a Spirit in addition to its other types.

Bulwark — Whenever Soulstone Servant attacks, if you control a creature with toughness 4 or greater, Soulstone Servant gets +2/+2 and gains flying until end of turn.

Sparkmage Prodigy has first strike as long as it's your turn.
Whenever you cast a cryptic spell, Sparkmage Prodigy deals 1 damage to each opponent. (Artifacts, enchantments, and modal spells are cryptic.)

Each creature you control that has been dealt damage this turn by a source you controlled has indestructible.

Vigilance
When Spear of the Folded Fan enters, if you control a legendary creature, you gain 4 life.

When Specialist Saboteur enters, choose one —
• Put a +1/+1 counter on Specialist
Saboteur.
• Destroy target enchantment.

When Spectral Kitsune enters, you may remove a counter from target player or permanent.

Prowess
Whenever you cast a noncreature spell, you may pay {R}. If you do, post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

Flying
When Spectre of Terror deals combat damage to a player, that player discards a card.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

When Speed Reader enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Add {R}{R}.

Instant and sorcery spells your opponents cast cost {1} more to cast.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card.

Flying
Spelldust Sprite gets +1/+1 as long as you control four or more creatures with flying.
If you would create a token, you may instead create a token that's a copy of Spelldust Sprite, except it doesn't have this ability.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{R}{R}: If an instant or sorcery source you control would deal damage to a permanent or player this turn, it deals that much damage plus 2 instead.

Whenever you cast a noncreature spell, you may pay {U}. If you do or the spell was cast from your graveyard, draw a card.

Haste
Whenever Spellmaw Crocodile deals combat damage to a player, draw a card.
Discard a card: Spellmaw Crocodile can't be blocked this turn.

Reach (This creature can block creatures with flying.)
When Spider Broodmother dies, create two 1/2 green Spider creature tokens with reach. (This creature can block creatures with flying.)

When Spiked Burrower dies, if it didn't have a counter on it, return it to the battlefield under your control with a +1/+1 counter or a lifelink counter on it.

Spined Spire enters tapped.
{T}: Add {U} or {R}.
{1}{U}{R}: Until end of turn, Spined Spire becomes a Lizard creature with menace in addition to its other types.
Scavenge {1}{U}{R}

Reach
Spined Tarantula gets +1/+1 for each creature with flying your opponents control.

When Spirit of the Sands enters, if you cast it, target opponent gains control of it.
At the beginning of your end step, draw three cards, then discard two cards.

Flash
If an opponent would gain life or damage to a permanent or opponent would be prevented, instead Spirit-Lantern Incendiary deals 1 damage to that permanent or opponent.

Flying
Whenever another creature you control dies, creatures you control get +1/+1 until end of turn.

Vigilance, reach
{T}: Splitshaft Deadeye deals damage equal to its power to target creature with flying.

Flash
When Splitting Image enters, you may pay {2} any number of times. Whenever you do, copy target spell. You may reselect modes and choose new targets for the copies.