Whenever a Merfolk you control deals combat damage to a player, draw a card.

Flash

When Seal Away enters, exile target tapped creature an opponent controls until Seal Away leaves the battlefield.

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Sacrifice Seal of Fire: It deals 2 damage to any target.

Sacrifice Seal of Removal: Return target creature to its owner's hand.

As Seal of the Guildpact enters, choose two colors.

Each spell you cast costs less to cast for each of the chosen colors it is.

Sealock Monster can't attack unless defending player controls an Island.

: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

When Sealock Monster becomes monstrous, target land becomes an Island in addition to its other types.

Look at the top five cards of your library. You may put any number of them into your hand and the rest into your graveyard. You lose 3 life for each card you put into your hand this way.

Flying

When Searchlight Companion enters, create a 1/1 colorless Spirit creature token.

Searing Blaze deals 1 damage to target player or planeswalker and 1 damage to target creature that player or that planeswalker's controller controls.

Landfall — If you had a land enter the battlefield under your control this turn, Searing Blaze deals 3 damage to that player or planeswalker and 3 damage to that creature instead.

Searing Flesh deals 7 damage to target opponent or planeswalker.

Raid — At the beginning of your end step, if you attacked this turn, create a 1/1 red Goblin creature token.

Whenever Seascape Aerialist or another Ally you control enters, you may have Ally creatures you control gain flying until end of turn.

Seaside Citadel enters tapped.

: Add , , or .

Choose one or both —

• Return target creature card from your graveyard to your hand.

• Return target enchantment card from your graveyard to your hand.

Add one mana of any color. (Then exile this card. You may cast the creature later from exile.)

Discard a card: Tap Seasoned Hallowblade. It gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Tasty (This creature can be attacked directly. If it is attacked, it can't block creatures that didn't attack it.)

As Secluded Glen enters, you may reveal a Faerie card from your hand. If you don't, Secluded Glen enters tapped.

: Add or .

Nonland permanents you control and permanent spells you control are enchantments in addition to their other types.

(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Exile target nonland card from your graveyard. Search your library for any number of cards with the same name as that card, reveal them, put them into your hand, then shuffle.

Enchant land

When Security Blockade enters, create a 2/2 white Knight creature token with vigilance.

Enchanted land has ": Prevent the next 1 damage that would be dealt to you this turn."

All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp."

All Slivers have ": Regenerate this permanent." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

When Sedraxis Alchemist enters, if you control a blue permanent, return target nonland permanent to its owner's hand.

Whenever a land enters, its controller creates a 1/1 green Snake creature token.

Vigilance, haste

Valiant — Whenever Seedglaive Mentor becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.

Undaunted (This spell costs less to cast for each opponent.)

Return up to two target cards from your graveyard to your hand. Exile Seeds of Renewal.

Seek two nonland cards, then put a card from your hand on the bottom of your library.

Mill seven cards. Then put all cards that have an Adventure from among the milled cards into your hand.

: Seeker of Sunlight explores. Activate only as a sorcery. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Menace (This creature can't be blocked except by two or more creatures.)

Whenever one or more artifacts and/or creatures you control are put into a graveyard from the battlefield, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

: Add .

, : Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

: Add .

, Sacrifice Seething Landscape: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Cycling (, Discard this card: Draw a card.)

Flying, vigilance

Discard a land card: Seismic Assault deals 2 damage to any target.

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.

Sejiri Glacier enters tapped.

: Add .

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

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.

Flying

Pay 2 life: Return Selenia, Dark Angel to its owner's hand.

: Add or .

, , Sacrifice Selesnya Cluestone: Draw a card.

, , Tap an untapped creature you control: Create a 1/1 green Saproling creature token.

: Create a 1/1 green Saproling creature token.

: Creatures you control get +1/+1 until end of turn.

: Add or .

, , Sacrifice Selesnya Locket: Draw two cards.

Selesnya Sanctuary enters tapped.

When Selesnya Sanctuary enters, return a land you control to its owner's hand.

: Add .

, : Add .

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.