msem-instigator

Enchant creature
Enchanted creature gets -X/-X, where X is 1 plus the number of counters on it.

Return target creature card with mana value 5 or less from your graveyard to the battlefield.
Metamorph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

[+2]: Up to one target creature gains deathtouch until your next upkeep.
[–3]: Target player sacrifices a creature and discards a card.
[–8]: Exile all creature cards from all graveyards, then create an X/X black Horror creature token with indestructible, where X is the total power of creatures exiled this way.

All creatures get -2/-2 until end of turn. If a creature an opponent controls would die this turn, exile it instead.

Whenever Malignant Afflicted perseveres, destroy target creature an opponent controls that dealt damage this turn. (A creature perseveres when it survives damage.)

{2}: Exile up to two target cards in a single graveyard. If two creature cards were exiled this way, create a 1/1 blue Elemental creature token with flying.

Put any number of target creature cards from your graveyard on top of your library.
You draw two cards, and you lose 2 life.

Enchant creature
Enchanted creature gets -3/-3.

When Manglehorn Hunter enters, draw a card and you lose 1 life.

Glitch—Pay 3 life. (Remove one [restriction] for each time you pay the glitch cost.)
Create a 6/6 black Demon artifact creature token with flying, trample, [“This creature can't attack players with 10 or more life,”] [and “This creature can't block creatures with power 4 or less.”]

Manifest a creature card at random from your graveyard. (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.)

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{5}{B}, Sacrifice Manipulations of the Div: It deals 4 damage to target player or battle and you gain 4 life. Activate only as a sorcery.

Enchant creature
When Mantle of the Returned enters, return target creature card from your graveyard to the battlefield. It's a Zombie in addition to its other types.
Enchanted creature gets +1/+1 for each Zombie you control.

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return another target creature card from your graveyard to your hand.

Flying, lifelink
Your opponents can't search libraries.
{B}, Pay 2 life, Discard a card: Search your library for a card, then shuffle and put that card on top.

Enchant opponent
Whenever enchanted player searches their library, you may search your library for a card, put it into your hand, then shuffle.

Skip your draw step.
At the beginning of your end step, discard a card. If you do, create a 4/4 white Angel creature token with flying. If you can't, sacrifice Mark of Hubris.

{1}{W}: Markov Fencer gains first strike until end of turn. You gain 1 life.

Menace
When Marrow Raptor enters, you may sacrifice a land or exile a land card from your graveyard. If you do, put a +1/+1 counter on it.

Until end of turn, target creature gets +3/+0 and gains “When this creature dies, return it to the battlefield tapped under its owner's control.”
Foretell {B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Improve {B} ({B}: 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.)
Whenever a nontoken creature you control dies, if it was embattled, you may pay {B}. If you do, create a 2/2 black Zombie creature token. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

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.

Sacrifice a creature: Put a +1/+1 counter on Masked Assailant. It gains menace until end of turn. Activate only as a sorcery.

Flying
When Masked Stalker enters, target player discards a card.

Whenever one or more cards are put into exile from anywhere, target opponent loses 1 life.
Whenever one or more creatures you control deal combat damage to a player, you may pay 2 life. If you do, purge. (Exile two cards that share a type from graveyards. If you do, draw a card.)