Choose one —
• Skysnipe deals 5 damage to target creature with flying.
• Put a +1/+1 counter and a reach counter on target creature. Untap it.

Whenever you cast an instant or sorcery spell, Skyward Magus gets +1/+1 and gains flying until end of turn.

Sleeper Insurgent doesn't untap during your untap step.
Whenever Sleeper Insurgent becomes the target of a spell or ability you control, untap it. This ability triggers only once each turn.

Flash
Flying
When Sleeper Strix enters, tap up to one target creature.
You may look at an additional card each time you surveil.

Flying
Favored
Whenever another legendary nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of it, except it has no name, it isn't legendary, and it is a Zombie.

When Slumbering Grove enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Spellcharge 8

Enchant land you control
Enchanted land is a 6/6 green Serpent creature with hexproof and haste. It's still a land.
When enchanted land dies, return that card to its owner's hand.

Once each turn, when Smart Shopper enters or you cast a creature spell, you may create a Berry token. If three or more types of mana were spent to cast it, create two of those tokens instead.

Whenever Smooth Operator deals combat damage to a player, draw a card.

Equipped creature gets +1/+1.
As long as equipped creature was activated this turn, it gets an additional +2/+2 and can attack as though it were untapped.
Equip {2}

When Snowscryer enters, surveil 3.

Return target creature to its owner's hand. If you controlled it, create a token that's a copy of it. Otherwise, create a 0/0 colorless Robot artifact creature token with a +1/+1 counter on it.

When Sola enters, create a Treasure token.
{2}, Sacrifice a Treasure: You gain 3 life.
{2}, Sacrifice a Treasure: Draw a card.

Each creature you control enters with an additional +1/+1 counter on it if you cast it.
Whenever an Elemental creature you control enters, you gain life equal to its power.

Create two 1/1 colorless Servo artifact creature tokens. Scry 1.

When Soothing Singer enters, exile target nonland permanent you don't control until Soothing Singer leaves the battlefield.
{1}{W}: Soothing Singer gets +0/+2 until end of turn.

Flying
Drop — When Soul Melter enters, if you didn't cast any creature spells during your last turn, each opponent loses 2 life and you gain 2 life.

Flying
When Soul's Sunset enters, exile up to two target cards from graveyards. You gain 2 life.
Surface {4}{B}{B}

When Soul-Guide Lantern enters, exile target card from a graveyard.
{T}, Sacrifice Soul-Guide Lantern: Exile each opponent's graveyard.
{1}, {T}, Sacrifice Soul-Guide Lantern: Draw a card.

Return up to three target cards from your graveyard to your hand. Exile Soulless Archive.

Haste
At the beginning of your end step, if a creature died this turn, put a +1/+1 counter on Soundforged Tyrant.

Prevent all damage that would be dealt to Soundproof Transport by creatures blocking it.

At the beginning of your end step, if you control three or more untapped lands, up to one target nonland permanent doesn't untap during its controller's next untap step.

Flying
Nonland permanents you control have phasing.
Whenever Spacetime Seraph phases out, until your next turn, your life total can't change and you have protection from everything.

Counter target activated or triggered ability from a nonland source. If a creature's ability is countered this way, you may pay {1}{C}. If you do, exile that creature.