msem-instigator

When Smoldering Husk dies, it deals 2 damage to any target.
{2}{R}: Smoldering Husk gets +2/+0 until end of turn.

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

Prowess, trample
During your turn, each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost plus “Pay X life, where X is this card's mana value.”

{T}: For each color among enchantments you control, add one mana of that color.
{2}{G}{G}, Sacrifice Sower of Seeds: Shuffle any number of enchantment cards from your graveyard into your library. Create an X/X black Horror creature token, where X is the number of enchantment cards shuffled into your library this way.

Whenever Sower of Virulent Thoughts attacks, you may return a creature you control to its owner's hand. If you do, put a +1/+1 counter on target creature you control.

Choose one or more —
• Counter target activated ability or triggered ability.
• Prevent all combat damage that would be dealt this turn.

Flying
When Spectre of Terror deals combat damage to a player, that player discards a card.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card.

Flying, ward {3}
Whenever Sphinx of Myriad Futures attacks, look at the top three cards of your library and reveal one of them. The defending player may have you put the revealed card into your hand. If they don't, put the other two cards into your hand. Then put the remaining cards into your graveyard.

Spinerock Canyon enters tapped unless you control a basic land.
{T}: Add {R} or {W}.

Splendid Scenery enters tapped unless you control a basic land.
{T}: Add {G} or {W}.

When Spoiled Prince enters, each player sacrifices a creature with the greatest power among creatures they control.

Reveal cards from the top of your library until you reveal a land card, then put that card onto the battlefield tapped. You may put another card revealed this way on top of your library. Put the rest of the cards revealed this way on the bottom in a random order.

Equipped creature gets +1/+1.
At the beginning of combat on your turn, choose flying, first strike, vigilance, trample, or haste. Equipped creature gains that ability until end of turn.
Equip {2}

Whenever a permanent you control leaves the battlefield, if it had counters on it, you may put those counters on Stage Magician.
At the beginning of your end step, you may move any number of counters from Stage Magician onto target permanent you control.

{T}: Add {C}.
{3}, {T}: Aetherize target permanent you control. Activate only as a sorcery. (To aetherize, create a token that's a copy of it, then exile that token.)

Until end of turn, if a source you don't control would deal damage to you or cause you to lose life, mill that many cards instead.

Create a 3/3 black Demon Horror creature token.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Creature cards in your graveyard have revive. The revive cost is equal to their mana cost. (Pay that creature's mana cost, Exile that card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever you gain life, each opponent loses 1 life.

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.

When Stonefall Golem leaves the battlefield, destroy target permanent.

Flying
Stormcloud Drake gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever Stormcloud Drake attacks, tap target creature defending player controls.

At the beginning of your upkeep, mill two cards.
{1}{G}, Sacrifice Strange Discovery: Return target card from your graveyard to your hand.