msem-instigator

Monumental Siege deals 5 damage divided as you choose among any number of targets. Whenever a creature dealt damage this way this turn dies, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Gloam Gullet gets +1/+1 and has menace as long as you own a land card in exile or in your graveyard.

When Unmasker of Fate's Design enters, look at target player's hand. Choose a nonland card from it and exile that card with a puzzle counter on it. As long as that card has a puzzle counter on it, that player may pay {2} and 1 life at any time. If they do, return the exiled card to their hand.

Ravenous Grue enters with a menace counter on it.
{5}{B}{B}, Remove a menace counter from Ravenous Grue: Destroy target creature.

When Celestial Scythe enters, attach it to target Angel, Demon, Faerie, or Spirit you control.
Equipped creature gets +2/+1.
Equip {2}

{1}, {T}: Tap target creature. Rising Sun Ascetic deals 1 damage to that creature's controller.

Reach
When Risti Watchkeeper enters, rediscover a creature card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a creature card. Otherwise, put it back or into your graveyard.)

Wanderer's Sky enters tapped.
As Wanderer's Sky enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {W} or {U}.

Vanguard — Whenever a creature you control attacks alone, it gets +1/+1 and gains menace until end of turn.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
Whenever you cast an instant or sorcery spell, Noirohpo Renegade gets +1/+0 until end of turn.

Primal {1}{W}{W} (During your turn, you may cast this spell for {1}{W}{W} instead of playing a land.)
Return target creature card from your graveyard to the battlefield.

Counter target spell with no subtypes. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Sanguine Oracle enters tapped.
{4}{B}, {T}, Sacrifice Sanguine Oracle: Target player discards two cards. Activate only as a sorcery.

When Slyten Analyst enters, you may search your library for a card, then shuffle and put that card on top. If you do, you lose 2 life.

(Choose only one work as a sorcery to add its ability.)
When Fables of the Ill-Fated enters, destroy target nonland permanent.
{B}: The Witch's Temple
Whenever a nonland permanent you control dies, each opponent loses 1 life.
{3}{G}: Enter the Nest
{3}{G}, Sacrifice two lands: Create a 0/0 green Wurm creature token with “This creature gets +1/+1 for each permanent card in your graveyard.” Activate only as a sorcery.

As an additional cost to cast this spell, sacrifice a land.
Create a 6/6 red Wurm creature token with “This creature can't be blocked by creatures with flying.”

Fall of the Axe deals 3 damage to any target.

Gain control of target creature until end of turn. Untap it. Until end of turn, it gains haste and “This creature can't be blocked.”
{1}, Discard Cruel Heartbeat: Add one mana of any color. Scry 1.

Look at the top five cards of your library. You may reveal a Scout or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Hollowghast, the Iron Phantom enters with three +1/+1 counters on it.
If damage would be dealt to Hollowghast, prevent that damage. Remove a +1/+1 counter from Hollowghast.

Distribute four +1/+1 counters among up to two target lands you control. Those lands become 0/0 Elemental creatures with haste until end of turn. If you're attacking, tap those lands. They're attacking.
Showcase {3}{R}{G} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Sodden Path enters tapped unless you control one or fewer other lands.
{T}: Add {G} or {U}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Trample
Whenever a creature you don't control dies, you gain 2 life.
Whenever you gain life, put that many +1/+1 counters on target creature you control.

Create a token that's a copy of target creature you control.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)