Starlight Spectacular

Parade! — At the beginning of combat on your turn, choose creatures you control one at a time until each creature you control has been chosen. Each of those creatures gets +1/+1 until end of turn for each creature chosen before it. (Places everyone! The first creature in line gets +0/+0.)

Seize the Secrets

This spell costs {1} less to cast if you've committed a crime this turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Draw two cards.

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Space Marine Devastator

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Grav-cannon — When Space Marine Devastator enters, destroy up to one target artifact or enchantment.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Fluros of Myra's Marvels

As Fluros of Myra's Marvels enters, choose a number greater than 0.
Whenever you cast a spell with power, toughness, or loyalty equal to the chosen number, target artifact or creature becomes an artifact creature with base power and toughness X/X until end of turn, where X is the chosen number.
Partner

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Shelter

Target creature you control gains protection from the color of your choice until end of turn.
Draw a card.

Serene Master

Whenever Serene Master blocks, exchange its power and the power of target creature it's blocking until end of combat.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Sol Talisman

Suspend 3—{1} (Rather than cast this card from your hand, pay {1} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}: Add {C}{C}.

Secrets of the Golden City

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Draw two cards. If you have the city's blessing, draw three cards instead.

Spell Snuff

Counter target spell.
Fateful hour — If you have 5 or less life, draw a card.

Sprite Noble

Flying
Other creatures you control with flying get +0/+1.
{T}: Other creatures you control with flying get +1/+0 until end of turn.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Student of Warfare

Level up {W} ({W}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-6
3/3
First strike
LEVEL 7+
4/4
Double strike

Serum Sovereign

Flying
Whenever you cast a noncreature spell, put an oil counter on Serum Sovereign.
{U}, Remove an oil counter from Serum Sovereign: Draw a card, then scry 2.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Selfless Savior

Sacrifice Selfless Savior: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Securitron Squadron

Squad {3} (As an additional cost to cast this spell, you may pay {3} any number of times. When this creature enters, create that many tokens that are copies of it.)
Vigilance
Whenever a creature token you control enters, put a +1/+1 counter on it.

Spirited Companion

When Spirited Companion enters, draw a card.

Scourge of Fleets

When Scourge of Fleets enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Skyhunter Strike Force

Flying
Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Lieutenant — As long as you control your commander, other creatures you control have melee.

Serra Redeemer

Flying
Whenever another creature you control with power 2 or less enters, put two +1/+1 counters on that creature.

Sphinx of Foresight

You may reveal this card from your opening hand. If you do, scry 3 at the beginning of your first upkeep.
Flying
At the beginning of your upkeep, scry 1.

Sigil of the New Dawn

Whenever a creature is put into your graveyard from the battlefield, you may pay {1}{W}. If you do, return that card to your hand.

Sky Diamond

Serendib Sorcerer

{T}: Target creature other than Serendib Sorcerer has base power and toughness 0/2 until end of turn.

Staying Power

"Until end of turn" and "this turn" effects don't end.

Stalwart Pathlighter

Vigilance
Coven — At the beginning of combat on your turn, if you control three or more creatures with different powers, creatures you control gain indestructible until end of turn.

Spelltithe Enforcer

Whenever an opponent casts a spell, that player sacrifices a permanent of their choice unless they pay {1}.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Island

Shape Stealer

Whenever Shape Stealer blocks or becomes blocked by a creature, change Shape Stealer's base power and toughness to that creature's power and toughness until end of turn.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, Serra Ascendant gets +5/+5 and has flying.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Spell Crumple

Counter target spell. If that spell is countered this way, put it on the bottom of its owner's library instead of into that player's graveyard. Put Spell Crumple on the bottom of its owner's library.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Snapcaster Mage

Flash
When Snapcaster Mage enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Azorius Signet

Soul Warden

Whenever another creature enters, you gain 1 life.

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Soul of Theros

Vigilance
{4}{W}{W}: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.
{4}{W}{W}, Exile Soul of Theros from your graveyard: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Sejiri Glacier

Sejiri Glacier enters tapped.
{T}: Add {W}.

Sejiri Shelter

Target creature you control gains protection from the color of your choice until end of turn.

Sejiri Shelter // Sejiri Glacier

Spear of Heliod

Creatures you control get +1/+1.
{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Senate Guildmage

{W}, {T}: You gain 2 life.
{U}, {T}: Draw a card, then discard a card.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Shark Typhoon

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle Shark Typhoon, create an X/X blue Shark creature token with flying.

Serra Paragon

Flying
Once during each of your turns, you may play a land from your graveyard or cast a permanent spell with mana value 3 or less from your graveyard. If you do, it gains "When this permanent is put into a graveyard from the battlefield, exile it and you gain 2 life."

Katerina of Myra's Marvels

As Katerina of Myra's Marvels enters, choose a letter.
Whenever you cast a spell whose name begins with the chosen letter, create a white 2/2 Cat creature token with flying.
Partner (You can have two commanders if they both have partner.)

Serum Visions

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Sculpted Sunburst

Choose a creature you control, then each opponent chooses a creature they control with equal or lesser power. If you chose a creature this way, exile each creature not chosen by any player this way.

Sol Ring

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Plains

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Spirit of the Spires

Flying
Other creatures you control with flying get +0/+1.

Silver Scrutiny

You may cast Silver Scrutiny as though it had flash if X is 3 or less.
Draw X cards.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Sram's Expertise

Create three 1/1 colorless Servo artifact creature tokens.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Staff of the Storyteller

When Staff of the Storyteller enters, create a 1/1 white Spirit creature token with flying.
Whenever you create one or more creature tokens, put a story counter on Staff of the Storyteller.
{W}, {T}, Remove a story counter from Staff of the Storyteller: Draw a card.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Usher to Safety

Return target permanent you control to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Shepherd of the Flock

Shepherd of the Flock // Usher to Safety

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Secure the Wastes

Create X 1/1 white Warrior creature tokens.

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Song of the Worldsoul

Whenever you cast a spell, populate. (Create a token that's a copy of a creature token you control.)