msem-instigator

Flying
Whenever you cast a creature spell, if Script Spirit is in your graveyard, you may have it become a copy of that spell until end of turn.

When Sear, Forged of Lava enters, create a 3/3 red Panda creature token, then attach it to that token.
Equipped creature gets +3/+3, has flying, haste, and “Whenever this creature dies, it deals 3 damage to target opponent or planeswalker.”
Equip {2}{R}{R}

Flying
Whenever Searshot Dragon deals combat damage to a player, it deals that much damage to target creature that player controls.
{1}{R}: Searshot Dragon gets +1/+0 until end of turn.

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}: Target player mills two cards.

Flash
Flying
When Seeker Amalgam enters, you may counter target spell with mana value less than or equal to the number of Elementals you control.

As long as a creature you control has flying, creatures you control have flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Flying
Whenever Seer of Clear Skies or another creature you control with flying attacks, that creature gets +1/+1 until end of turn.

When Seishin Tidekeeper enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have flying.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Sejiri Skyhunter, it gains flying until end of turn.

Death knell — Put a +1/+1, flying, lifelink, or menace counter on Senn, the Haunting Gaze, then trigger a death knell of another permanent you control. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.

Flying, vigilance
Whenever Sepulchral Guide attacks, prevent all combat damage that would be dealt to another target creature you control this turn. If that creature has two or more counters on it, untap it.

Flying
When Seraph of Renewal leaves the battlefield, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Flying, vigilance, lifelink
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Flying
Whenever you cycle Seraph of the Stage or it attacks, audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)
Basic landcycling {1}{W} ({1}{W}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

Serene Chapel enters tapped unless you control a basic Plains.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Serene Chapel becomes a 2/1 white Spirit Cleric creature with flying and “Whenever this creature attacks, you may exile target card from a graveyard.” It's still a land.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Serul Cove Escort encourages a creature, that creature gains flying until end of turn.

This spell can't be countered.
Flying, protection from cryptic
Whenever you cast a cryptic spell, cast a Sphinx spell, or draw a card, investigate.
{T}, Sacrifice ten Clues: You win the game.

[+1]: Create a 1/1 green Scout creature token. If you control six or more lands, also create a 1/1 white Bird creature token with flying.
[–1]: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.
[–5]: You get an emblem with “Whenever each permanent you control becomes tapped for the first time each turn, untap it.”

Flying
When Sha Long enters, each player chooses an artifact they control, then sacrifices the rest. If they don't control an artifact, they may return an artifact card from their graveyard to the battlefield. Repeat this process for creatures, enchantments, and planeswalkers.

Discard a land card: Draw a card. Shardstorm Elemental gets +1/+0 and gains flying until end of turn. Activate only once each turn.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Spell you cast cost {1} less to cast as long as it's not your turn.

Flying
When Sharp-Eyed Wingmate enters, you may return target creature to its owner's hand.

Flash
Flying
When Sharuum, Archmagocrat enters, return to the battlefield all nonlegendary artifact cards in your graveyard that were put there from the battlefield this turn.