msem-instigator

Vigilance, trample
At the beginning of combat on your turn, put a +1/+1 counter on target legendary creature you control.

Flying, first strike, lifelink
When Stalwart Seraph enters, untap all creatures you control.

Flash (You may cast this spell any time you could cast an instant.)
When Stampede Instigator enters, target creature gets +2/+3 until end of turn.

Flying
Starbane Elemental's power and toughness are each equal to the number of creatures with flying you control.
When Starbane Elemental enters, destroy all creatures without flying.

Flying
Whenever Starborne Hellkite attacks, choose two—
• Starborne Hellkite deals 4 damage to any target.
• Destroy target artifact or land.
• Creatures you control get +2/+0 until end of turn.

Trample, ward {1}
Whenever Stardust Surveyor deals combat damage to a player, you may mill cards until you mill a creature card. When you do, return target creature card from your graveyard to your hand.

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.)
Each other creature you control gets +1/+1 for each creature you control with the same name as it. (A token's name is its creature types unless specified.)

Whenever Starlight Emissary harnesses a spell, draw a card.

Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may play Start Over without paying its mana cost.
Put target creature or planeswalker on the bottom of its owner's library.

Flash (You may cast this spell any time you could cast an instant.)
When Stasis Snare enters, exile target creature an opponent controls until Stasis Snare leaves the battlefield.

Create a 3/3 black Demon Horror creature token.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

When Steelcharm Obliterator enters, choose one —
• Put two +1/+1 counters on Steelcharm Obliterator.
• Target creature you control fights another target creature.

Flying
Vanguard — Whenever a creature you control attacks alone, you may put a +1/+1 counter on it.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Steelhoof Battlechief attacks, another target attacking creature you control gets +2/+2 and gains trample until end of turn.

Hexproof
Cycling {3} ({3}, Discard this card: Draw a card.)

Enchant creature
Enchanted creature's activated abilities can't be activated.
Prevent all damage that would be dealt by enchanted creature.

Flying
Whenever Stingsower attacks, you may pay {3}{B}{B}. If you do, target creature gets -1/-1 for each Insect you control until end of turn.

Take an extra turn after this one. At the beginning of that turn's upkeep, if you control a legendary creature, each opponent exiles the top card of their library. Until the end of that turn, you may play those cards and you may spend mana as though it were mana of any type to cast those spells.
Exile Stolen Moments.

Trample

Whenever Stonehoof Familiar is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)
Menagerie — As long as there are five or more creature types among creatures you control, all damage that would be dealt to you or other permanents you control is dealt to Stonehoof Familiar instead.

Destroy target artifact or nonbasic land.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Renown 3 (When this creature deals combat damage to a player, if it isn't renowned, put three +1/+1 counters on it and it becomes renowned.)

You may pay {1}{R}{R} and tap an untapped Knight you control rather than pay this spell's mana cost.
Target untapped creature you don't control blocks this turn if able. Other creatures can't block this turn.

Flying
Stormcloud Drake gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever Stormcloud Drake attacks, tap target creature defending player controls.

This spell can't be countered.
Flying
Dominance — Whenever Stormwing Ultrateryx becomes the target of a spell an opponent controls, if you control the creature with the greatest power or tied for the greatest power, counter that spell.