msem-instigator

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

You gain 1 life. Scry 1. Draw a card.

Equipped creature gets +1/+1.
Equip {1}

Shoupan Shrine enters tapped.
{T}: Add {B} or {R}.
{B/R}, {T}, Sacrifice Shoupan Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Whenever you create an Idol token, put a +1/+1 counter on Shrine of Elder Lords.
{T}: Add {C}.
{3}: Put a +1/+1 counter on Shrine of Elder Lords, then you may have it become a 0/0 Elemental creature with vigilance until end of turn. It's still a land.

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if you've cast a noncreature spell this turn.

{T}: Add {C}.
Shrine of the World-Shepherd's power and toughness are each equal to the number of differently named lands you control.
{3}{G}: Shrine of the World-Shepherd becomes a Beast creature in addition to its other types until end of turn.

{T}: Add {C}.
{T}: Choose a color. Add one mana of that color unless you control a permanent of that color. Spend this mana only to cast a permanent spell.

{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.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Shrouded Cackler can't block.

Frozen Hinterlands enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Until end of turn, Shrouded Rooftops becomes a 3/3 white and black Illusion creature with with lifelink 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.)

{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.

Shroudmaker's Domain enters tapped.
{T}: Add {W}.

({T}: Add {B} or {G}.)
Shuddering Node enters tapped.
{1}, {T}: Add {B}{B} or {G}{G}.

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.

Flash
Harmony — Another target creature gets +1/+0 and gains indestructible until end of turn.
When Siamang Tale-Singer enters, harmonize. (Trigger up to one harmony of a permanent you control.)

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.

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.

Creature tokens you control get +1/+0.

As long as Sigiled Scrollcase is attached to a creature you control, you have no maximum hand size.
Whenever equipped creature dies, draw a card.
Equip {1}

When Signet Ring enters, scry 1.
{2}, {T}, Sacrifice Signet Ring: Add two mana of different colors.

When Silence Dissent enters, each player exiles a card from their hand at random until Silence Dissent leaves the battlefield.
{1}{W}: Exile Silence Dissent. Return it to the battlefield under your control at the beginning of your next end step.

Enchant creature
When Silent Call enters, draw a card.
Enchanted creature attacks each combat if able.