msem-instigator

Strange Harbor enters the battlefield tapped unless you have 15 or less life.
{T}: Add {U} or {R}.

Prowess
Pay 2 life: Change a target of target spell or ability to Straw Intellectual.

Creatures blocking or blocked by Straw Officer have wither. (They deal damage to creatures in the form of -1/-1 counters.)

As Straw Simulacrum enters the battlefield, choose a creature type.
Straw Simulacrum is the chosen creature type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Strider Engine enters tapped and with a -1/-1 counter on it unless you spent at least three colors of mana to cast it.

Equipped creature gets +1/+1 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Stunning Cascade enters the battlefield tapped.
{T}: Add {U} or {R}.
{2}{U}{R}, {T}, Sacrifice Stunning Cascade: Draw a card.

As Sturdy Outpost enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

({T}: Add {B}.)
As Stygian Dunes enters the battlefield, you may pay 1 life. If you don't, Stygian Dunes enters the battlefield tapped.

Substack Ports enters the battlefield tapped.
{T}: Add {U} or {B}.
{U}{B}, {T}, Sacrifice Substack Ports: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

{2}: Other creatures you control get +1/+0 until end of turn.
Whenever Sun-Crowned Flagship attacks, each attacking creature you control gains trample until end of turn.
Crew 7 (Tap any number of creatures you control with total power 7 or greater: This Vehicle becomes an artifact creature until end of turn.)

Sundappled Scrub enters the battlefield tapped unless you control another Desert.
{T}: Add {G} or {W}.

Equipped creature gets +1/+0 and gains “Whenever this creature deals damage to a player or planeswalker, you may draw two cards. If you do, discard a card.”
Equip {2}

{1}, {T}: End the turn. Activate only during your turn.

As Sunflower Fields enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {R}, {G}, or {W}.

({T}: Add {G} or {W}.)
Sungrace Meadows enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sunken Cavern enters the battlefield tapped unless another player controls a land that could produce {U} or {R}.
{T}: Add {U} or {R}.

When Sunken Grave enters the battlefield, create a tapped 2/2 black Zombie creature token.
{5}, {T}, Sacrifice Sunken Grave: Create a tapped 2/2 black Zombie creature token.

Sunken Homestead enters the battlefield tapped.
{T}: Add {B}.
{2}{B}: Until end of turn, Sunken Homestead becomes a 2/2 Zombie creature with “When this creature dies, return it to the battlefield.” Activate only if you're horrific.

As Sunless Ridge enters the battlefield, you may tap an untapped creature you control. If you don't, Sunless Ridge enters the battlefield tapped.
{T}: Add {B} or {R}.

Sunlit Fissure enters the battlefield tapped.
{T}: Add {G} or {W}.
{2}{G}{W}: Until end of turn, Sunlit Fissure becomes a 3/5 green and white Elemental creature with with vigilance and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

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

({T}: Add {W}.)
As Sunlit Meadow enters the battlefield, you may pay 1 life. If you don't, Sunlit Meadow enters the battlefield tapped.
Basic lands you control have “{T}: Add {W}.”

({T}: Add {G} or {W}.)
As Sunlit Plaza enters the battlefield, you may pay {1}. If you don't, Sunlit Plaza enters the battlefield tapped.

Sunlit Ruins enters the battlefield tapped unless you control a Swamp.
{T}: Add {G} or {W}.