msem-instigator

{T}: Add {C}.
{T}, Tap an untapped artifact, creature, or land you control: Add one mana of any color.
{T}: Choose a card name, then reveal the top card of your library. If that card has the chosen name, you may sacrifice Sealed Archives and draw a card.

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

({T}: Add {U}.)
As Seaside Grotto enters, you may pay 1 life. If you don't, Seaside Grotto enters tapped.
Basic lands you control have “{T}: Add {U}.”

({T}: Add {G} or {U}.)
Secluded Cascade enters tapped unless you control two or more basic lands.

As Secluded Courtyard enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

{T}: Add {C}.
{T}, Reappropriate: Add {G} or {W}. (Exile exactly two cards from your hand and/or graveyard.)

({T}: Add {W} or {U}.)
Whenever Sedate Tundra becomes tapped, you lose 1 life unless you control two or more basic lands.

({T}: Add {G}.)
Seedshrine enters tapped.
When Seedshrine enters, you may put a +1/+1 counter on target creature.

{T}, Pay 1 life: Add {B} or {G}.
{1}, {T}, Sacrifice Seedy Bar: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Creatures with power less than Seer of the Hunt's power can't block it.

Whenever you scry, draw a card.

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Spirit creature token.

{T}: Add {C}.
{T}, Reappropriate: Add {U} or {B}. (Exile exactly two cards from your hand and/or graveyard.)

Serene Chapel enters tapped unless you control a basic Plains.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Serene Chapel becomes a 2/1 white Spirit Cleric creature with flying and “Whenever this creature attacks, you may exile target card from a graveyard.” It's still a land.

{T}: Add {G} or {U}. You lose 1 life unless you have less life than an opponent.

{T}, Sacrifice Serene Trail: Search your library for a Forest or Plains card and put it onto the battlefield tapped, then shuffle.

Serpentine Woods enters tapped.
{T}: Add {B} or {G}.
{2}{B}{G}, {T}, Sacrifice Serpentine Woods: Draw a card.

Enchant player
At the beginning of enchanted player's upkeep, that player creates a 1/1 white Soldier creature token.

{T}: Add {C}.
{5}{R}{G}, {T}: Transform Settled Satrapy.

Shadowcleft Hideout enters tapped.
{T}: Add {B}.
{T}, Pay 2 life, Sacrifice Shadowcleft Hideout: Draw a card.

({T}: Add {B}.)
Shadowed Slums enters tapped.
{B}, {T}, Reveal a black card from your hand: Target player loses 1 life.

You may play Shanty Town from your graveyard as long as seven or more cards are in your graveyard.
Shanty Town enters tapped.
{T}: Add {W} or {B}.
Cycling {1}{W}{B} ({1}{W}{B}, Discard this card: Draw a card.)

As Shardstone Rift enters, you may pay 2 life. If you don't, Shardstone Rift enters tapped.
{T}, Sacrifice Shardstone Rift: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Sheltered Haven enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}, {T}, Sacrifice Sheltered Haven: Draw a card.

{T}: Add {C}.
As long as Shengin Heartland is in your graveyard, lands you control have “{T}: Add {G} or {U}.”