Flash

When Selfless Squire enters, prevent all damage that would be dealt to you this turn.

Whenever damage that would be dealt to you is prevented, put that many +1/+1 counters on Selfless Squire.

Whenever Selhoff Occultist or another creature dies, target player mills a card.

When Seller of Songbirds enters, create a 1/1 white Bird creature token with flying.

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.

, : Add X mana in any combination of colors, where X is the greatest power among creatures you control.

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.

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

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

Flying

Whenever one or more other creatures die, put a +1/+1 counter on Sengir Connoisseur. This ability triggers only once each turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)

Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

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.

Enchant creature

Enchanted creature gets -3/-0.

When Sentinel of Lost Lore enters, choose one or more —

• Return target card you own in exile that has an Adventure to your hand.

• Put target card you don't own in exile that has an Adventure on the bottom of its owner's library.

• Exile target player's graveyard.

Vigilance

Whenever Sentinel of the Nameless City enters or attacks, create a Map token. (It's an artifact with ", , Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Haste

As long as an artifact entered the battlefield under your control this turn, creatures you control get +2/+2.

Battalion — Whenever Sentinel Sarah Lyons and at least two other creatures attack, Sentinel Sarah Lyons deals damage equal to the number of artifacts you control to target player.

Vigilance, reach

Whenever an instant or sorcery spell is cast during your turn, Sentinel Tower deals damage to any target equal to 1 plus the number of instant and sorcery spells cast before that spell this turn.

Flash

Enchant creature

Enchanted creature gets +1/+2 and has vigilance.

Addendum — When Sentinel's Mark enters, if you cast it during your main phase, enchanted creature gains lifelink until end of turn.

When Separatist Voidmage enters, you may return target creature to its owner's hand.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

When Sepulchral Primordial enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Flying

Whenever Seraph of New Phyrexia attacks, you may sacrifice another creature or artifact. If you do, Seraph of New Phyrexia gets +2/+1 until end of turn.

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.)

Flying

At the beginning of your upkeep, Serendib Efreet deals 1 damage to you.

Destroy target enchantment. You gain life equal to its mana value.

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

Flash

Enchant creature

Enchanted creature gets +1/+1.

: Regenerate enchanted creature.

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)

Deathtouch

Until end of turn, target creature becomes a blue Serpent with base power and toughness 5/5.

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is one plus the total number of instant and sorcery cards you own in exile and in your graveyard.

Devoid (This card has no color.)

Serpentine Spike deals 2 damage to target creature, 3 damage to another target creature, and 4 damage to a third target creature. If a creature dealt damage this way would die this turn, exile it instead.

Creatures with flying get +1/+1.

Flying, first strike

Whenever you cast a historic spell, Serra Disciple gets +1/+1 until end of turn. (Artifacts, legendaries, and Sagas are historic.)

Whenever Serra Inquisitors blocks or becomes blocked by one or more black creatures, Serra Inquisitors gets +2/+0 until end of turn.

Flying, vigilance

Flying

As Serra's Emissary enters, choose a card type.

You and creatures you control have protection from the chosen card type.

At the beginning of your upkeep, you may put a verse counter on Serra's Liturgy.

, Sacrifice Serra's Liturgy: Destroy up to X target artifacts and/or enchantments, where X is the number of verse counters on Serra's Liturgy.

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

When Serum Visionary enters, draw a card, then scry 2.

Flying

Whenever you cast a noncreature spell, put an oil counter on Serum-Core Chimera.

Remove three oil counters from Serum-Core Chimera: Draw a card. Then you may discard a nonland card. When you discard a card this way, Serum-Core Chimera deals 3 damage to target creature or planeswalker. Activate only as a sorcery.

Deathtouch

Whenever Servant of the Stinger deals combat damage to a player, if you've committed a crime this turn, you may sacrifice Servant of the Stinger. If you do, search your library for a card, put it into your hand, then shuffle. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

When Servo Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Servo artifact creature token.

Vigilance, haste

Heroic — Whenever you cast a spell that targets Setessan Battle Priest, you gain 2 life.

Flying

: Setessan Griffin gets +2/+2 until end of turn. Activate only once each turn.

Constellation — Whenever an enchantment you control enters, Setessan Skirmisher gets +1/+1 until end of turn.

Enchant creature you control

When Setessan Training enters, draw a card.

Enchanted creature gets +1/+0 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Choose one or both —

• Exile target creature you don't control.

• Exile target creature you control, then return it to the battlefield under its owner's control.

When Settlement Blacksmith enters, if you control an Equipment, draw a card.

Exile target creature and all other creatures with the same name as that creature.

Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Prevent all damage that would be dealt to Sevinne, the Chronoclasm.

Whenever you cast your first instant or sorcery spell from your graveyard each turn, copy that spell. You may choose new targets for the copy.