msem-instigator

Target player mills a card. Create a 3/2 colorless Horror creature token. Put a decayed counter on it. (It can't block. When it attacks, sacrifice it at end of combat.)

Destroy target creature with mana value 2 or less. If it was a token, you gain 2 life.

Rattlecage Terror enters tapped.
{1}{B}: Return Rattlecage Terror from your graveyard to your hand. When you do, another target creature card with mana value 3 or less in your graveyard gains this activated ability until end of turn, except it costs {1} more to activate.

Marrowskitter can't block and can't be blocked.
{3}{B}{B}: Return Marrowskitter from your graveyard to the battlefield. Create a token that's a copy of it.

Flash
When Gravetiller enters, you may exile target creature or planeswalker card from a graveyard. If it had mana value 4 or less, you may return it to its owner's hand. Otherwise, you may shuffle it into its owner's library.
Evoke {B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

When Goremound enters, target creature you don't control gets -3/-3 until end of turn. All other creatures you don't control with the same name as that creature get -1/-1 until end of turn.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Choose any number of target creature and/or planeswalker cards in your graveyard. Return one of them to the battlefield and put the rest on top of your library in any order.

Create a 3/2 colorless Horror creature token. All other creatures get -3/-3 until end of turn.

Choose one —
• Exile all creature tokens.
• Exile target creature or planeswalker.
• Each opponent exiles a card from their hand and loses 2 life.

When Duskling Stalker dies, if it didn't have any counters on it, return it to the battlefield with your choice of a deathtouch, lifelink, or +1/+1 counter on it.

Whenever another creature you control dies, each opponent loses 1 life and you gain 1 life. Then you may pay {B}. If you do, Disciple of Myriad Fates becomes a copy of that creature, except it has this ability.

At the beginning of your upkeep, you may sacrifice another creature. If that creature had mana value 2 or greater, create a 3/2 colorless Horror creature token. Otherwise, create a 1/1 colorless Human creature token.
Whenever you create a creature token, you may pay 2 life. If you do, put a menace counter on it.

[+1]: Each opponent loses 1 life and you gain 1 life. Mill a card. If you do, you may shuffle a card from your graveyard into your library.
[0]: Any number of target players each discard a card. If you have an insight counter, return up to one creature card from your graveyard to your hand.
[0]: You get an insight counter.
[–2]: Target creature gets -3/-3 until end of turn.

This spell costs {3} more to cast if it targets a card in an opponent's graveyard.
Choose target creature or planeswalker card in a graveyard that was put there from the battlefield this turn. Put that card onto the battlefield under your control.

Nightshaper's Domain enters tapped.
{T}: Add {B}.

{B}: Remove a counter from target permanent.
{3}{B}: Move a counter from target permanent onto Ashfeaster Ghouls. Ashfeaster Ghouls can't be blocked this turn.

You may have Warped Physiognomist enter as a copy of any creature on the battlefield with mana value 3 or less.

Once each turn, when Vedu, the Deepdrinker enters or you attack with one or more Horrors, you may tap up to two target permanents. If Vedu isn't a token, put two stun counters on each of those permanents.
{2}{U}{U}, Discard Vedu: Create a token that's a copy of Vedu, the Deepdrinker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of combat on your turn, target creature you control with mana value 3 or less can't be blocked this turn. If Streetwise Investigator has two or more counters on it, that creature gains vigilance until end of turn.

Create a 1/1 colorless Human creature token. Put your choice of a flying, vigilance, prowess, or hexproof counter on it. If you control a permanent with mana value 5 or greater, instead put any number of those counters and a +1/+1 counter on it.

[+1]: Tap target permanent. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
[0]: Put target artifact, instant, or sorcery card from your graveyard on top of your library. If you have an insight counter, you may return that card to your hand instead.
[0]: You get an insight counter.
[–1]: Target creature can't be blocked this turn. Until end of turn, whenever that creature deals damage to an opponent, you draw a card.

{1}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}{U}, {T}: Copy target spell you control. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

When Hideaway Agent enters, gain control of target nonland permanent with mana value 3 or less for as long as you control Hideaway Agent.

Prowess
When Grasper of Secrets enters, choose one —
• Return target creature to its owner's hand.
• Return target instant or sorcery card from your graveyard to your hand.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Flash
Enchant creature
Enchanted creature has base power and toughness 0/1 and loses all abilities and creature types.
{2}{U}: Return Fractured Persona to its owner's hand.