msem-instigator

Destroy target artifact or enchantment. You gain 4 life.

Soli Sanctuary enters tapped.
Satrapies you control have “{T}: Add {W} or {U}.”

Soli Temple enters tapped.
Satrapies you control have “{T}: Add {G} or {W}.”

({T}: Add {B} or {G}.)
Somber Marsh enters tapped.

Somber Meadow enters tapped.
{T}: Add {W} or {B}.
{1}, {T}: Add one mana of any color.

Whenever another creature you control enters, target opponent loses 1 life and you gain 1 life.
Sacrifice Somber River Bearer: Creatures you control gain indestructible until end of turn.

When Somnambulance enters, each player conjures a card named Fatigue and puts it on top of their library. (It's a colorless sorcery that costs {2} with “Draw a card.”)
Whenever a player casts a spell named Fatigue, you may draw a card. If you do, you lose 1 life.

Enchant permanent
Enchanted permanent is a land with “{T}: Add {G}{W}{U}” and loses all other card types and abilities.
{1}, Discard Song of Shoals: Add one mana of any color. Scry 1.

As Sorcerous Spyglass enters, look at an opponent's hand, then choose any card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Flying, lifelink
Morph {4}{B}
When Soul Cajoler is turned face up, manifest the bottom card of your library. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

{1}, {T}: Exile target card from a graveyard. Scry 1.
{T}, Exile Soul Gate: Exile all graveyards.

Destroy target creature unless its controller pays {3}.

Counter target creature spell unless its controller pays {2}.

Whenever another creature enters, you gain 1 life.

Tap two untapped creatures you control: Harmonize. (Trigger up to one harmony of one permanent you control.)
Harmony — Choose one —
• Soul of New Alores becomes a creature in addition to its other types until end of turn.
• Put two +1/+1 counters on target permanent.

{1}, {T}, Sacrifice Soul-Synthesizer: Look at the top seven cards of your library. You may reveal a card with an activated ability from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Soulblade enters, exile target creature card with mana value 3 or less from your graveyard.
Whenever equipped creature attacks, create a token that's a copy of a card exiled with Soulblade that's tapped and attacking. Exile the token at end of combat.
Equip {1}

Poisonous 3 (Whenever this creature deals combat damage to a player, that player gets three poison counters.)
When Soulbreaker of Mautakesh enters, target poisoned player sacrifices a creature.

Soulsmoke Adept gets +1/+0 and has lifelink as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Spend only black mana on X.
Any number of target players each draw X cards and lose X life.

Flash
Flying
Whenever you cast a spell during an opponent's turn, target permanent doesn't untap during its controller's next untap step.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
When Sower of Wishes enters, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest back on top in any order.

Enchant land
Enchanted land's name is Flowering Expanse.
Whenever enchanted land is tapped for mana, add one mana of any color.

{T}: Add {C}.
{T}: Add one mana of any color among planeswalkers you control.
{1}, {T}: Put a loyalty counter on target planeswalker that activated a loyalty ability this turn.

Spark New Life deals X damage to any target. You may put up to X land cards from your hand and/or graveyard onto the battlefield.