Whenever you cast an instant or sorcery spell, you may put a charge counter on Surrakar Spellblade.

Whenever Surrakar Spellblade deals combat damage to a player, you may draw X cards, where X is the number of charge counters on it.

Whenever Surtland Flinger attacks, you may sacrifice another creature. When you do, Surtland Flinger deals damage equal to the sacrificed creature's power to any target. If the sacrificed creature was a Giant, Surtland Flinger deals twice that much damage instead.

When Surveillance Monitor enters the battlefield, you may collect evidence 4. (Exile cards with total mana value 4 or greater from your graveyard.)

Whenever you collect evidence, create a 1/1 colorless Thopter artifact creature token with flying.

First strike

, Exile Survivor of Korlis from your graveyard: Scry 2.

If you would planeswalk, instead look at the top two cards of your planar deck, put one on the bottom of your planar deck and the other on top, then planeswalk.

: Add .

Doctor's companion (You can have two commanders if the other is the Doctor.)

Whenever Suspicious Nanny deals combat damage to a player, it reassembles target Contraption that player controls. (Gain control of it and move it onto one of your sprockets.)

Suspicious Stowaway can't be blocked.

Whenever Suspicious Stowaway deals combat damage to a player, draw a card, then discard a card.

Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Damage that would reduce your life total to less than 1 reduces it to 1 instead.

Flying

: Regenerate target creature.

, : Create a colorless snow artifact token named Icy Manalith with ": Add one mana of any color."

, : Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

, : Target creature gains shroud until end of turn. Activate only during your upkeep. (It can't be the target of spells or abilities.)

Raid — Swaggering Corsair enters the battlefield with a +1/+1 counter on it if you attacked this turn.

Flying

If a source would deal damage to Swans of Bryn Argoll, prevent that damage. The source's controller draws cards equal to the damage prevented this way.

Flying

Swarm of Bloodflies enters the battlefield with two +1/+1 counters on it.

Whenever another creature dies, put a +1/+1 counter on Swarm of Bloodflies.

Swarm of Rats's power is equal to the number of Rats you control.

Swarm Shambler enters the battlefield with a +1/+1 counter on it.

Whenever a creature you control with a +1/+1 counter on it becomes the target of a spell an opponent controls, create a 1/1 green Insect creature token.

, : Put a +1/+1 counter on Swarm Shambler.

When Swarming Goblins enters the battlefield, roll a d20.

1–9 | Create a 1/1 red Goblin creature token.

10–19 | Create two of those tokens.

20 | Create three of those tokens.

Vigilance

Whenever Swathcutter Giant attacks, it deals 1 damage to each creature defending player controls.

Flash

Cascade

Reach

When Sweet-Gum Recluse enters the battlefield, put three +1/+1 counters on each of any number of target creatures that entered the battlefield this turn.

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Exile target nontoken creature. Return it to the battlefield under its owner's control at the beginning of the next end step.

Flying

When Swift Warkite enters the battlefield, you may put a creature card with mana value 3 or less from your hand or graveyard onto the battlefield. That creature gains haste. Return it to your hand at the beginning of the next end step.

Flying, haste

When Swiftgear Drake enters the battlefield, put up to one target card from a graveyard on the bottom of its owner's library.

: Target creature you control becomes the color or colors of your choice until end of turn.

Flash

Flying

Swooping Protector enters the battlefield with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Flying

: Swooping Talon loses flying until end of turn.

Provoke (Whenever this creature attacks, you may have target creature defending player controls untap and block it if able.)

: Target attacking creature gets -1/-0 until end of turn.

Swordsworn Cavalier has first strike as long as another Knight entered the battlefield under your control this turn.

: Sworn Defender's power becomes the toughness of target creature blocking or being blocked by Sworn Defender minus 1 until end of turn, and Sworn Defender's toughness becomes 1 plus the power of that creature until end of turn.

First strike, haste

Sanctified Rules of Combat — When Sycorax Commander enters the battlefield, each opponent faces a villainous choice — That opponent discards all the cards in their hand, then draws that many cards minus one, or Sycorax Commander deals damage to that player equal to the number of cards in their hand.

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Vigilance

As long as you control six or more lands, Sylvan Advocate and land creatures you control get +2/+2.

When Sylvan Brushstrider enters the battlefield, you gain 2 life.

When Sylvan Hierophant dies, exile Sylvan Hierophant, then return another target creature card from your graveyard to your hand.

Reach

When Sylvan Primordial enters the battlefield, for each opponent, destroy target noncreature permanent that player controls. For each permanent destroyed this way, search your library for a Forest card and put that card onto the battlefield tapped. Then shuffle.

Sacrifice a land: Target creature you control gains shroud until end of turn. (It can't be the target of spells or abilities.)

Sylvan Yeti's power is equal to the number of cards in your hand.

: Add one mana of any color that a land an opponent controls could produce.

When Symbiotic Beast dies, create four 1/1 green Insect creature tokens.

When Symbiotic Wurm dies, create seven 1/1 green Insect creature tokens.

When Synapse Necromage dies, create two 1/1 black Fungus creature tokens with "This creature can't block."

All Sliver creatures have vigilance.

Extort (Whenever you cast a spell, you may pay . If you do, each opponent loses 1 life and you gain that much life.)

Extort (Whenever you cast a spell, you may pay . If you do, each opponent loses 1 life and you gain that much life.)

At the beginning of each end step, if you gained 4 or more life this turn, investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")

Flying

Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

, Sacrifice an artifact: Put a +1/+1 counter on Syndicate Trafficker. It gains indestructible until end of turn.

When you control no other artifacts, sacrifice Synod Centurion.

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)

You may have Synth Infiltrator enter the battlefield as a copy of any creature on the battlefield, except it's a Synth artifact creature in addition to its other types.

First strike

Whenever Syr Alin, the Lion's Claw attacks, other creatures you control get +1/+1 until end of turn.

Knightlifelink (Damage dealt by Knights you control also causes you to gain that much life.)

: Syr Cadian, Knight Owl gains vigilance until end of turn. Activate only from sunrise to sunset.

: Syr Cadian, Knight Owl gains flying until end of turn. Activate only from sunset to sunrise.