msem-instigator

When Lightblessed Claymore enters, attach it to target creature you control.
Equipped creature gets +2/+0 and has lifelink.
Equip {4}

When Stolen Light enters, exile target nonland permanent an opponent controls until Stolen Light leaves the battlefield.
{W}{U}{B}{R}{G}: Put a permanent card exiled with Stolen Light onto the battlefield under your control. It's a 3/3 Horror creature in addition to its other types.

Gain control of target non-Pirate, non-Rogue creature until end of turn. Untap that creature. It gains haste until end of turn. Pirates and Rogues you control get +1/+0 until end of turn.

When Digital Divinity enters, put a +1/+1 counter on each creature you control.
Whenever you gain life, you may return Digital Divinity to its owner's hand.

As you cast instant and sorcery spells this turn, they gain “Draw a card” and “This spell deals 1 damage to any target.”

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

Creatures you control get +1/+0 for each color among permanents you control and have haste.
Whenever you cast a white, blue, black, or green instant or sorcery spell, copy it for each of its colors. You may choose new targets for the copies.

When Seafloor Shrine enters and when you sacrifice it, create a 1/1 white Merfolk creature token.
{1}{W}, Sacrifice Seafloor Shrine: Draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Return target permanent to its owner's hand.

When you cast this spell, copy it. You may choose new targets for the copy. (Copies keep functions.)
Draw a card.

Flash
Whenever Operative POSH attacks or you cast a green or red spell, exile up to one target nontoken permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Whenever Shah's Caravan attacks, creatures you control get +1/+1 until end of turn. If you control three or more Satrapies, creatures you control can't be blocked by creatures with power 2 or less this turn.
Satrapycycling {2} ({2}, Discard this card: Search your library for a Satrapy card, reveal it, put it into your hand, then shuffle.)

Flash
When Remnant Spotter enters, put target permanent card from your graveyard on top of your library.

Whenever you scry, Taker of Tithes gets +1/+0 until end of turn and can't be blocked this turn.

Tap up to two target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Denied Attempt, you may tap target creature.

Whenever a card is put into your graveyard from your library, you may put it on top of your library.
{U}{B}, Sacrifice Rallios' Return: Until end of turn, you may play target card from your graveyard. If that spell would be put into a graveyard, exile it instead.

When Twilight Vigil enters, scry 2, then put a night counter on it.
Death knell — Put a night counter on Twilight Vigil. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Sacrifice Twilight Vigil: For each night counter on it, you gain 1 life and trigger up to one death knell of a permanent you control.

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

Flying

Bloodsand Gulch enters tapped unless you control another Desert.
{T}: Add {B} or {R}.

Blazing Volley deals 1 damage to each creature your opponents control.

Flying
{3}{W}, {T}: Exile another target creature you control, then return that card to the battlefield under your control.

Flying
When Tempest Stormcaster enters, if a permanent you control left the battlefield this turn, you may have target player draw a card.

Reach
Whenever another creature you control dies, surveil 1.
{T}, Sacrifice a non-Spider creature: Create a 1/2 green Spider creature with reach.

Whenever H.S.S. Demeter becomes blocked by a creature, gain control of that creature.
Whenever H.S.S. Demeter deals combat damage to a player, draw two cards.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)