msem-instigator

When Splinter of Creation enters, you may exile any number of land cards from your graveyard.
You may play lands exiled with Splinter of Creation.

Flying, haste
Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Splitflame Phoenix dies, you may pay {R}. If you do, return it to its owner's hand.

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.

Flying
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Trample (This creature can deal excess combat damage to defending player or planeswalker while attacking.)
Sprareos Yearling gets +4/+4 as long as you control five or more lands.

At the beginning of each upkeep, untap up to two target lands.

Lifelink
When Stalked Healer enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flash
When Stalker in the Mist enters, up to one target creature gets -1/-0 until end of turn.

Stalwart Guardian has first strike as long as it's attacking.
Augmented — When Stalwart Guardian enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, create two 1/1 blue Elemental creature tokens with flying.

Other creatures you control named Starfall Dancer get +2/+2.

Whenever Starfall Instructor attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Each opponent loses 2 life.

Whenever Stargaze Spirit or another creature dies, you may gain 1 life.
Revive {3}{W} ({3}{W}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

At the beginning of your end step, you may sacrifice a permanent. When you do, return target creature card from your graveyard to your hand.

Flying
Whenever an opponent draws a card except for the first time each turn, create a 1/1 blue Elemental creature token with flying.
Foresight — Whenever you draw your second card each turn, creatures you control get +1/+1 until end of turn.

Menace
Discard a creature card or sacrifice a creature or exile a creature card from your graveyard: Put a +1/+1 counter on Starving Stalker. Activate only once each turn.

{1}{W}: Untap Steadfast Infantry.

Flying
Whenever a player shuffles their library, Steamquiver Strix deals 2 damage to that player.

When Steamwork Musicians enters, creatures you control get +1/+0 until end of turn.

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.)

Steelborn Apprentice gets +1/+1 as long as you control an Equipment.

Vigilance
Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
{T}: Prevent the next X damage that would be dealt to target creature this turn, where X is Steelclad Investigator's power.

Flash
Advance {3}{W} (Cast this for {3}{W} to advance it as it enters. {3}{W}: Advance this as a sorcery.)
Whenever Steelwoven Soldier advances, it gets +2/+2 until end of turn.

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
When Steeple Deadeye enters, if the trial was failed, you gain 3 life and put a +1/+1 counter on Steeple Deadeye.

When Stiff Butler enters, search target player's library for up to two cards and exile them. Then that player shuffles.

When Still-Smoke Skirmisher dies, each opponent loses 1 life and you gain 1 life. Then return Still-Smoke Skirmisher to the battlefield at the beginning of the next end step if it was sacrificed.