Aphetto Exterminator

Morph {3}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, target creature gets -3/-3 until end of turn.

Unnerving Grasp

Return up to one target nonland permanent to its owner's hand. Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Cursed Windbreaker

When this Equipment enters, manifest dread, then attach this Equipment to that creature. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
Equipped creature has flying.
Equip {3}

Yedora, Grave Gardener

Whenever another nontoken creature you control dies, you may return it to the battlefield face down under its owner's control. It's a Forest land. (It has no other types or abilities.)

Pine Walker

Morph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever this creature or another creature you control is turned face up, untap that creature.

Innocuous Rat

When this creature dies, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Forest

Cryptid Inspector

Vigilance
Whenever a face-down permanent you control enters and whenever this creature or another permanent you control is turned face up, put a +1/+1 counter on this creature.

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Echo Tracer

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, return target creature to its owner's hand.

Break Down the Door

Choose one —
• Exile target artifact.
• Exile target enchantment.
• Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Growing Dread

Flash
When this enchantment enters, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
Whenever you turn a permanent face up, put a +1/+1 counter on it.

Golgari Rot Farm

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Brine Elemental

Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, each opponent skips their next untap step.

Chromeshell Crab

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Patron of the Wild

Morph {2}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, target creature gets +3/+3 until end of turn.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Paranormal Analyst

Whenever you manifest dread, put a card you put into your graveyard this way into your hand.

Sol Ring

Jeweled Bird

Remove this card from your deck before playing if you're not playing for ante.
{T}: Ante this artifact. If you do, put all other cards you own from the ante into your graveyard, then draw a card.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Roshan, Hidden Magister

Other creatures you control are Assassins in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Face-down creatures you control have menace.
Whenever a permanent you control is turned face up, you draw a card and you lose 1 life.

Thornwood Falls

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {U}.

Manifest Dread

Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Voidmage Apprentice

Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, counter target spell.

Threats Around Every Corner

When this enchantment enters, manifest dread.
Whenever a face-down permanent you control enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Twist Reality

Choose one —
• Counter target spell.
• Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Swamp

Skinthinner

Morph {3}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, destroy target nonblack creature. It can't be regenerated.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Overgrown Zealot

{T}: Add one mana of any color.
{T}: Add two mana of any one color. Spend this mana only to turn permanents face up.

Island

Oblivious Bookworm

At the beginning of your end step, you may draw a card. If you do, discard a card unless a permanent entered the battlefield face down under your control this turn or you turned a permanent face up this turn.