Whenever Segmented Wurm becomes the target of a spell or ability, put a -1/-1 counter on it.

Flash (You may cast this spell any time you could cast an instant.)

When Seht's Tiger enters, you gain protection from the color of your choice until end of turn. (You can't be targeted, dealt damage, or enchanted by anything of the chosen color.)

When Seismic Elemental enters, creatures without flying can't block this turn.

Seismic Rupture deals 2 damage to each creature without flying.

Creatures without flying can't block this turn.

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Target creature gets +1/+1 and gains first strike until end of turn.

Destroy target nonwhite, nonblack creature. Create a 1/1 white Spirit creature token with flying.

Haunt (When this spell card is put into a graveyard after resolving, exile it haunting target creature.)

When the creature Seize the Soul haunts dies, destroy target nonwhite, nonblack creature. Create a 1/1 white Spirit creature token with flying.

Each opponent chooses fame or fortune. For each player who chose fame, gain control of a creature that player controls until end of turn. Untap those creatures and they gain haste until end of turn. For each player who chose fortune, you draw a card and create a Treasure token.

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

Whenever another nontoken creature you control dies, create a 3/1 black and red Graveborn creature token with haste.

Reveal the top seven cards of your library. Choose from among them a card with flying, a card with first strike, and so on for double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance. Put one of the chosen cards onto the battlefield, the other chosen cards into your hand, and the rest into your graveyard.

Each player chooses a color. Then exile each permanent unless it's colorless or it's only the color its controller chose.

: Add or .

, , Sacrifice Selesnya Cluestone: Draw a card.

This land enters tapped.

: Add or .

Reach (This creature can block creatures with flying.)

Selesnya Sagittars can block an additional creature each combat.

: Regenerate Selesnya Sentry.

Search your library for a basic land card and reveal it. If there's a tree in its art, put it onto the battlefield tapped. Otherwise, put it into your hand. Then shuffle.

, Sacrifice Selfless Cathar: Creatures you control get +1/+1 until end of turn.

Flying

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

, Discard a creature card: Draw a card.

When Sell-Sword Brute dies, it deals 2 damage to you.

Parley — : Each player reveals the top card of their library. For each nonland card revealed this way, add and you gain 1 life. Then each player draws a card.

Council's dilemma — Starting with you, each player votes for wild or free. Reveal cards from the top of your library until you reveal a creature card for each wild vote. Put those creature cards onto the battlefield, then shuffle the rest into your library. You may put a permanent card from your hand onto the battlefield for each free vote.

At the beginning of your upkeep, choose target opponent. This turn, that player can't cast spells or activate abilities and plays with their hand revealed. You may play lands and cast spells from that player's hand this turn.

Flying

When Senate Griffin enters, scry 1.

Artifacts you control are Clues in addition to their other types and have ", Sacrifice this artifact: Draw a card."

Whenever you sacrifice a Clue, target creature can't be blocked this turn.

When Sengir Autocrat enters, create three 0/1 black Serf creature tokens.

When Sengir Autocrat leaves the battlefield, exile all Serf tokens.

Flying

, Exile Sengir Nosferatu: Create a 1/2 black Bat creature token with flying. It has ", Sacrifice this creature: Return an exiled card named Sengir Nosferatu to the battlefield under its owner's control."

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with Sensation Gorger, you may reveal it. If you do, each player discards their hand, then draws four cards.

: Look at the top three cards of your library, then put them back in any order.

: Draw a card, then put Sensei's Divining Top on top of its owner's library.

: Change Sentinel's base toughness to 1 plus the power of target creature blocking or blocked by Sentinel. <I>(This effect lasts indefinitely.)</I>

Vigilance (Attacking doesn't cause this creature to tap.)

At the beginning of combat on each opponent's turn, tap target creature that player controls.

Flash

When Sentinel of the Pearl Trident enters, you may exile target historic permanent you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step. (Artifacts, legendaries, and Sagas are historic.)

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

When Sentinel Totem enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

, Exile Sentinel Totem: Exile all graveyards.

Enchant creature

Enchanted creature gets +1/+1 and has vigilance.

Escape—, Exile two other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Flash

Flying

Defender

At the beginning of combat on your turn, you may clash with an opponent. If you win, Sentry Oak gets +2/+0 and loses defender until end of turn. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Flying, vigilance

, Exile Senu, Keen-Eyed Protector: You gain 2 life and scry 2.

When a legendary creature you control attacks and isn't blocked, if Senu is exiled, put it onto the battlefield attacking.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Whenever Septic Rats attacks, if defending player is poisoned, it gets +1/+1 until end of turn.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)

Flying

Seraph of the Masses's power and toughness are each equal to the number of creatures you control.

Flying

Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)

When Seraph Sanctuary enters, you gain 1 life.

Whenever an Angel you control enters, you gain 1 life.

: Add .

First strike, lifelink

Whenever Seraphic Steed attacks while saddled, create a 3/3 white Angel creature token with flying.

Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Destroy all Auras.

When Serene Sleuth enters, investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")

At the beginning of combat on your turn, investigate for each goaded creature you control. Then each creature you control is no longer goaded.

Prevent all combat damage X target creatures would deal this turn.

Trample, haste

Share Intelligence — Whenever Sergeant John Benton deals combat damage to a player, you and that player each draw that many cards.

When Serpent Assassin enters, you may destroy target nonblack creature.