msem-instigator

This spell costs {2} less to cast if you activated an ability that's not a mana ability this turn.
Searing Grace deals 3 damage to any target.

Target creature gains winnow until end of turn if you attacked this turn. Searing Insult deals 2 damage to that creature. (Damage dealt to it also causes its controller to lose that much life.)

Reverberate {3}{R} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Searing Pulse deals 2 damage to any target.

Haste
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Menace
Whenever Searing Sandwurm is dealt damage, it deals that much damage to target player or planeswalker.

Choose one or both —
• Exile target artifact.
• Put a -1/-1 counter on target creature.

Flying
Whenever Searshot Dragon deals combat damage to a player, it deals that much damage to target creature that player controls.
{1}{R}: Searshot Dragon gets +1/+0 until end of turn.

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}.”

Seaside Skimmer can't be blocked if you've cast a Dragon spell or Adventure spell this turn.

Trample
Seasoned Adventurer enters with two +1/+1 counters if you control seven or more lands.

{3}{G}: Seasoned Farmer gets +2/+2 until end of turn.

Whenever Seasoned Lookout deals combat damage to a player, it voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Seasoned Lookout phases in, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.

Search your library for up to four basic land cards with different names, reveal them, put them into your hand, then shuffle.

Vigilance
Seawise Swain gets +1/+1 as long as you control an artifact.
Seawise Swain gets +1/+1 as long as you control an enchantment.

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.)

When Secluded Monument enters, choose a color.
Whenever you cast a spell of the chosen color, Secluded Monument becomes a 5/5 Golem creature until end of turn.

Defender (This creature can't attack.)
Adorned — Secluded Wildborn can attack as though it didn't have defender as long as it's equipped and/or enchanted.

Augmented — At the beginning of combat on your turn, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Second Wave Explorer.

Whenever a permanent you control leaves the battlefield, Second-Day Slayings deals 1 damage to each opponent.

When Second-Stage Actress enters, audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)
As long as it's your turn, Second-Stage Actress has first strike.

Secret Lagoon enters tapped. When it enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {G} or {U}.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Return up to two target cards from your graveyard to your hand. Exile Secret Stash.

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}: Target player mills two cards.