Cavern Whisperer

Mutate {3}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Menace (This creature can't be blocked except by two or more creatures.)
Whenever this creature mutates, each opponent discards a card.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Death's Approach

Enchant creature
Enchanted creature gets -X/-X, where X is the number of creature cards in its controller's graveyard.

Lingering Death

Enchant creature
At the beginning of the end step of enchanted creature's controller, that player sacrifices that creature.

Clutch of Undeath

Enchant creature
Enchanted creature gets +3/+3 as long as it's a Zombie. Otherwise, it gets -3/-3.

Fear

Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.)
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Nyxborn Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Enchanted creature gets +2/+1.

Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters the battlefield, you may return Dragon Shadow from your graveyard to the battlefield attached to that creature.

World-Weary

Enchant creature
Enchanted creature gets -4/-4.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Feebleness

Flash
Enchant creature
Enchanted creature gets -2/-1.

Pharika's Libation

Choose one —
• Target opponent sacrifices a creature.
• Target opponent sacrifices an enchantment.

Midnight Covenant

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."

Yoke of the Damned

Enchant creature
When a creature dies, destroy enchanted creature.

Shade's Form

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."
When enchanted creature dies, return that card to the battlefield under your control.

Ragged Veins

Flash
Enchant creature
Whenever enchanted creature is dealt damage, its controller loses that much life.

Altar of the Pantheon

Your devotion to each color and each combination of colors is increased by one.
{T}: Add one mana of any color. If you control a God, a Demigod, or a legendary enchantment, you gain 1 life.

Swamp

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Necromantic Thirst

Enchant creature
Whenever enchanted creature deals combat damage to a player, you may return target creature card from your graveyard to your hand.

Driver of the Dead

When Driver of the Dead dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Cavern Lampad

Bestow {5}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Enchanted creature gets +2/+2 and has intimidate.

Ancestral Vengeance

Enchant creature
When Ancestral Vengeance enters the battlefield, put a +1/+1 counter on target creature you control.
Enchanted creature gets -1/-1.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Sign in Blood

Target player draws two cards and loses 2 life.

Infernal Scarring

Enchant creature
Enchanted creature gets +2/+0 and has "When this creature dies, draw a card."

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Clinging Darkness

Enchant creature
Enchanted creature gets -4/-1.

Unnatural Endurance

Devoid (This card has no color.)
Target creature gets +2/+0 until end of turn. Regenerate it.

Oblivion's Hunger

Target creature you control gains indestructible until end of turn. Draw a card if that creature has a +1/+1 counter on it. (Damage and effects that say "destroy" don't destroy the creature.)

Scourgemark

Enchant creature
When Scourgemark enters the battlefield, draw a card.
Enchanted creature gets +1/+0.

Grisly Transformation

Enchant creature
When Grisly Transformation enters the battlefield, draw a card.
Enchanted creature has intimidate. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Professor's Warning

Choose one —
• Put a +1/+1 counter on target creature.
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Death's-Head Buzzard

Flying
When Death's-Head Buzzard dies, all creatures get -1/-1 until end of turn.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Boon of Emrakul

Enchant creature
Enchanted creature gets +3/-3.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Precipitous Drop

Enchant creature
When Precipitous Drop enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.)
Enchanted creature gets -2/-2. It gets -5/-5 instead as long as you've completed a dungeon.

Untamed Hunger

Enchant creature
Enchanted creature gets +2/+1 and has menace. (It can't be blocked except by two or more creatures.)

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Dreadbringer Lampads

Constellation — Whenever Dreadbringer Lampads or another enchantment enters the battlefield under your control, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Hateful Eidolon

Lifelink
Whenever an enchanted creature dies, draw a card for each Aura you controlled that was attached to it.

Mire's Grasp

Enchant creature
Enchanted creature gets -3/-3.

Cast into Darkness

Enchant creature
Enchanted creature gets -2/-0 and can't block.

Nyx Infusion

Enchant creature
Enchanted creature gets +2/+2 as long as it's an enchantment. Otherwise, it gets -2/-2.

Mogis's Favor

Enchant creature
Enchanted creature gets +2/-1.
Escape—{2}{B}, Exile two other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Strands of Undeath

Enchant creature
When Strands of Undeath enters the battlefield, target player discards two cards.
{B}: Regenerate enchanted creature.

Withercrown

Enchant creature
Enchanted creature has base power 0 and has "At the beginning of your upkeep, you lose 1 life unless you sacrifice this creature."

Viper's Kiss

Enchant creature
Enchanted creature gets -1/-1, and its activated abilities can't be activated.

Baleful Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Enchanted creature gets +1/+1 and has deathtouch.

Debilitating Injury

Enchant creature
Enchanted creature gets -2/-2.

Weight of the Underworld

Enchant creature
Enchanted creature gets -3/-2.

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment enters the battlefield under your control, each opponent loses 1 life.

Dark Favor

Enchant creature
When Dark Favor enters the battlefield, you lose 1 life.
Enchanted creature gets +3/+1.

Charcoal Diamond

Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.

Crippling Blight

Enchant creature
Enchanted creature gets -1/-1 and can't block.

Dead Weight

Molting Snakeskin

Enchant creature
Enchanted creature gets +2/+0 and has "{2}{B}: Regenerate this creature."

Stronghold Discipline

Each player loses 1 life for each creature they control.

Boon of Erebos

Target creature gets +2/+0 until end of turn. Regenerate it. You lose 2 life.

Feed the Serpent

Mortuary Mire

Mortuary Mire enters the battlefield tapped.
When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Dogged Pursuit

At the beginning of your end step, each opponent loses 1 life and you gain 1 life.