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

Seaside Citadel enters the battlefield tapped.

: Add , , or .

When you control no Islands, sacrifice Seasinger.

You may choose not to untap Seasinger during your untap step.

: Gain control of target creature whose controller controls an Island for as long as you control Seasinger and Seasinger remains tapped.

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.)

Lifelink

When Seasoned Dungeoneer enters the battlefield, you take the initiative.

Whenever you attack, target attacking Cleric, Rogue, Warrior, or Wizard gains protection from creatures until end of turn. It explores. (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 the creature, then put the card back or put it into your graveyard.)

Whenever Seasoned Marshal attacks, you may tap target creature.

, Exile the top four cards of your library: The next time a source of your choice would deal damage to you this turn, prevent that damage.

Return any number of cards with different mana values from your graveyard to your hand. Put Seasons Past on the bottom of its owner's library.

: Add .

: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with Secret Base.

Create X 1/1 white Warrior creature tokens.

When Seedguide Ash dies, you may search your library for up to three Forest cards, put them onto the battlefield tapped, then shuffle.

Exile the top two cards of your library. Until your next end step, you may play those cards.

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

When Self-Assembler enters the battlefield, you may search your library for an Assembly-Worker creature card, reveal it, put it into your hand, then shuffle.

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.

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

Whenever Serpentine Basilisk deals combat damage to a creature, destroy that creature at end of combat.

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

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.

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

: Each opponent loses 2 life and you gain 2 life. Activate only if there are four or more creature cards in your graveyard.

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

When Shaper Parasite is turned face up, target creature gets +2/-2 or -2/+2 until end of turn.

Choose one —

• Target opponent reveals their hand and discards all colorless nonland cards.

• Target opponent reveals their hand and discards all multicolored cards.

As Shatterskull, the Hammer Pass enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

: Add .

Sheriff of Safe Passage enters the battlefield with a +1/+1 counter on it plus an additional +1/+1 counter on it for each other creature you control.

Plot (You may pay and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Prevent all damage that would be dealt to target creature this turn.

Flying, vigilance

Shinechaser gets +1/+1 as long as you control an artifact.

Shinechaser gets +1/+1 as long as you control an enchantment.

Shivan Oasis enters the battlefield tapped.

: Add or .

: Exile Shorecrasher Elemental, then return it to the battlefield face down under its owner's control.

: Shorecrasher Elemental gets +1/-1 or -1/+1 until end of turn.

Megamorph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

As an additional cost to cast this spell, sacrifice an artifact.

Shrapnel Blast deals 5 damage to any target.

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

: Sighted-Caste Sorcerer gains shroud until end of turn. (It can't be the target of spells or abilities.)

: Destroy target blocking creature at end of combat.

Creatures with power greater than Silumgar Assassin's power can't block it.

Megamorph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

When Silumgar Assassin is turned face up, destroy target creature with power 3 or less an opponent controls.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Ninjutsu abilities you activate cost less to activate.

Other Ninja and Rogue creatures you control get +1/+1.

Graft 3 (This creature enters the battlefield with three +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)

: Until end of turn, target creature with a +1/+1 counter on it gains "Whenever this creature deals combat damage to a creature, destroy that creature at end of combat."

When Siona, Captain of the Pyleas enters the battlefield, look at the top seven cards of your library. You may reveal an Aura card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Whenever an Aura you control becomes attached to a creature you control, create a 1/1 white Human Soldier creature token.

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.

−3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

−7: Destroy all non-Dragon creatures.

Sivitri, Dragon Master can be your commander.

Enchant creature

Enchanted creature attacks each combat if able.

When enchanted creature dies, return Skin Invasion to the battlefield transformed under your control.

Reach

Whenever you cast a spell with mana value 5 or greater, create a Food token. (It's an artifact with ", , Sacrifice this artifact: You gain 3 life.")

Whenever Skyclaw Thrash attacks, flip a coin. If you win the flip, Skyclaw Thrash gets +1/+1 and gains flying until end of turn.

Skyline Cascade enters the battlefield tapped.

When Skyline Cascade enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.

: Add .

Trample

As Skyshroud War Beast enters the battlefield, choose an opponent.

Skyshroud War Beast's power and toughness are each equal to the number of nonbasic lands the chosen player controls.

( can be paid with either or 2 life.)

Haste

Whenever Slashing Tiger becomes blocked, it gets +2/+2 until end of turn.

Flying

Whenever Slith Ascendant deals combat damage to a player, put a +1/+1 counter on it.

Destroy target artifact.

Draw a card.

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

Lifelink

Flash

When Snapcaster Mage enters the battlefield, 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.)

Solar Blast deals 3 damage to any target.

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

When you cycle Solar Blast, you may have it deal 1 damage to any target.