msem-instigator

Enchant creature you control
At the beginning of your upkeep, create a token that's a copy of enchanted creature.

{8}{U}{U}: Monstrosity 5. (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)
When Shipway Whale becomes monstrous, target player exiles all cards in their library, then shuffles their graveyard into their library.

This spell has flash as long as an opponent is cursed.
Return target creature to its owner's hand.
Draw a card.

Whenever you cast a noncreature spell, Shiverpass Taskmage explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Flying
When Shoal Raker enters, draw a card if an opponent is cursed.

Reveal the top four cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand. Shuffle the other and up to four cards from your graveyard into your library.

When Shojiro, the Wavewaker enters, submerge up to eight target creatures your opponents control. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Target creature gains hexproof until end of turn.
Monument {2}{U} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

{3}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When Shorecrash Octopus becomes monstrous, return target instant or sorcery card from your graveyard to your hand.

Whenever Shoreline Stormers deals damage to a player, draw a card.
{2}{U}: Target creature can't be blocked this turn.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Marked creatures your opponents control lose all abilities.

Flying
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Flying, vigilance

{2}{U}: Target creature can't be blocked this turn.

Put a +1/+1 counter on target creature. It gains hexproof until end of turn.

Return target nonland permanent to its owner's hand.
Inscribed creature gets +1/+1 and has flying.
Inscribe {3}{U} ({3}{U}: 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.)

Enchant creature
When Shrouded Spoils enters, draw two cards.
Enchanted creature can't be blocked.

Draw a card. If this is the third spell you've cast this turn, create a 2/2 blue Drake creature token with flying. If this is the sixth spell you've cast this turn, exile it, then return up to three target instant and/or sorcery cards from your graveyard to your hand and untap up to six lands.

Vigilance
Whenever Sibling of All Elements attacks, it gains flying until end of turn if you control a creature with flying. The same is true for first strike, double strike, deathtouch, indestructible, lifelink, menace, and trample.

Flash
Whenever you cast Siflir, Elder Pawn or another spell, if you paid an alternate or additional cost to cast it, draw a card.
Wander {3}{U}{U} (You may cast this from the battlefield for its wander cost.)

Draw three cards, then discard a card unless you've catalyzed three or more times this turn.

When Sift Through False Leads enters, exile the top five cards of your library, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{2}, Sacrifice a Clue: Put a card exiled with Sift Through False Leads into your hand.

When Sights Beyond enters, scry 3.
Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, draw a card.

Prowess
{T}: Catalyze, then catalyze again. Activate only if Sigil Slinger's power is 5 or greater. (The next spell you cast this turn costs {2} less to cast.)

{T}: Scry 1.