msem-instigator

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.

Flying, prowess
When Spellwarden Sphinx enters, tap up to three nonland permanents. Those permanents don't untap during their controllers' next untap step.

{1}, {T}, Exile Sphere of Sorcery: Return target noncreature, nonland card from your graveyard to your hand.
{8}, {T}, Exile Sphere of Sorcery: Return any number of target noncreature, nonland cards from your graveyard to your hand.

Spire Runner can't be blocked.
Whenever Spire Runner deals combat damage to a player, you may draw a card. If you do, discard a card.

Exile target artifact an opponent controls. Until end of turn, you may cast a copy of that card. (You still pay its costs.)

Flying
Whenever you foretell a card or cast a foretold spell, you may scry 1.

Equipped creature gets +1/+1.
At the beginning of combat on your turn, choose flying, first strike, vigilance, trample, or haste. Equipped creature gains that ability until end of turn.
Equip {2}

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.

This spell costs {1} less to cast if it targets an embattled creature. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Put two +1/+1 counters on target creature you control and untap it. It gains hexproof and trample until end of turn.

(Transform this if it's not attached to a creature. Pay {2}{U} as a sorcery to unattach it.)
Enchant creature you control
Steed of the Loch's rider gets +2/+1.
Whenever Steed of the Loch's rider attacks, you may tap target creature an opponent controls.

When Stilthorpe Falconer enters, create a 1/1 white Bird creature token with flying.

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.

Reach
Stonebark Incinerator gets +2/+0 and has trample as long as you control a Dwarf.
Stonebark Incinerator gets +0/+2 and has vigilance as long as you control a Elf.

This spell costs {2} less to cast if you control a legendary creature.
Search your library for a creature or land card, reveal it, put it into your hand, then shuffle.

Whenever you cast an instant or sorcery spell, you may attach Stormbreaker's Edge to target creature you control.
Equipped creature gets +3/+0.
Equip {3}

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.

As Straw Simulacrum enters, choose a creature type.
Straw Simulacrum is the chosen creature type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Ward {1}
Streetslipper can't be blocked.
Whenever you foretell a card or cast a foretold spell, put a +1/+1 counter on Streetslipper.

Target creature gains hexproof and indestructible until end of turn. If it's legendary, put a +1/+1 counter on it.

Enchant creature
When Strike Fear enters, draw a card.
When enchanted creature attacks, target creature can't block this turn.

Improve {G} ({G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever an Elf you control dies, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

Exile target artifact or enchantment. If its mana value is 3 or less, draw a card.

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

({T}: Add {W}.)
As Sunlit Meadow enters, you may pay 1 life. If you don't, Sunlit Meadow enters tapped.
Basic lands you control have “{T}: Add {W}.”