msem-instigator

Sculpted Observatory enters tapped.
{T}: Add {W} or {U}.
{1}, {T}: Add one mana of any color.

Whenever you sacrifice a permanent, you may pay {1}. If you do, you draw a card and you gain 1 life.

At the beginning of your upkeep, if six or more cards are in your graveyard, you may transform Scuttling Gnat.

Draw a card, then draw cards equal to the number of cards named Sea Cache in your graveyard.

Sea Of Skies Beyond enters tapped.
Whenever you cast a noncreature spell, put a creation counter on Sea Of Skies Beyond.
{T}, Remove ten creation counters from Sea Of Skies Beyond and sacrifice it: Shuffle your hand into your library, then draw five cards.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When Sea's Allure enters, gain control of target creature for as long Sea's Allure remains on the battlefield.

Flash
When Seabreen Nullmage enters, counter target activated or triggered ability. (A triggered ability uses the words “when,” “whenever,” or “at”. Mana abilities can't be targeted.)

Concord — {1}{G}: Until end of turn, Seadrake Rider gets +2/+3 and must be blocked if able. Activate only during your turn, only once each turn, and only if there are four or more card types among permanents you control.

Flash
{U}, Sacrifice Seal of Approval: Counter target spell unless its controller pays {2}.

Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.
Scry 1.

When Sealed Riftway enters, exile up to one target card from a graveyard.
{2}, {T}, Sacrifice Sealed Riftway: Exile target player's graveyard. Draw a card.

Sear Flesh deals 3 damage to target creature or planeswalker. If you've cast another spell this turn, it deals 5 damage instead.

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 permanent you control deals 2 damage to any target.
Inscribe {2}{R}{R} ({2}{R}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

First mate—Each nonland card in your starting deck targets or has an ability that targets. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Hexproof
Whenever a permanent you don't control becomes the target of a spell or ability you control, create a token that's a copy of that permanent.

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.

({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}.”

This spell can't be countered.
Draw a card.
Reprise {2}{U} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

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

{T}, Sacrifice a creature: Target player discards a card and loses 1 life. Activate only as a sorcery.

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

Target creature gets +1/+1 and gains first strike until end of turn.
Fabled {3}{W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Reveal the top three cards of your library. Put one into your hand and the rest on the bottom of your library in any order.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

As long as you control four or more lands, Seeker of Untouched Beauty gets +2/+2 and has trample.
When Seeker of Untouched Beauty dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.