msem-instigator

{U}, Sacrifice Seal of Insights: Look at the top four cards of your library. Put one into your hand and the rest on the bottom of your library in any order.

Choose one —
• Destroy target artifact or enchantment.
• Target creature you control explores twice. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card in your graveyard.)

Reveal the top five cards of your library. You may put an instant or sorcery card from among them into your hand. Put the rest into your graveyard.

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.)

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

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

{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.

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.

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}.

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

Scry 2, then draw two cards. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

When Seductive Seashell enters, target player mills two cards.
{2}, Sacrifice Seductive Seashell: Target player mills four cards.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.(Cast a copy of this spell once while this creature is on the battlefield.)

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Each cursed opponent must attack with at least one creature each combat if able.

Create three 0/1 green Plant creature tokens.

Draw three cards. Then discard two cards unless you discard a land card.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a land you control enters, add a quest counter.
Create a 1/1 Scout creature token that's all colors.
Creatures you control get +2/+1 until end of turn.
Creatures you control get +1/+1 until end of turn.

Prevent all damage that would be dealt to creatures and to you this turn.