Gray Merchant of Asphodel

When this creature enters, 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.)

Rakdos Carnarium

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Death Denied

Return X target creature cards from your graveyard to your hand.

Command Tower

Bloodfell Caves

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

Sulfurous Mire

({T}: Add {B} or {R}.)
This land enters tapped.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Weapon Surge

Target creature you control gets +1/+0 and gains first strike until end of turn.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Night's Whisper

Cosmotronic Wave

Cosmotronic Wave deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Swamp

Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

Arcane Spyglass

{2}, {T}, Sacrifice a land: Draw a card and put a charge counter on this artifact.
Remove three charge counters from this artifact: Draw a card.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Rat Colony

This creature gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Nasty End

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards. If the sacrificed creature was legendary, draw three cards instead.

Terminate

Destroy target creature. It can't be regenerated.

Crash Through

Creatures you control gain trample until end of turn. (Each of those creature can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Warlord's Fury

Creatures you control gain first strike until end of turn.
Draw a card.

Sign in Blood

Target player draws two cards and loses 2 life.

Feed the Swarm

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

Falkenrath Noble

Flying
Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Tramway Station

This land enters tapped.
{T}: Add {B} or {R}.
{2}{B}{R}, {T}, Sacrifice this land: Draw a card.

Geothermal Bog

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Dross Skullbomb

{1}, Sacrifice this artifact: Draw a card.
{2}{B}, Sacrifice this artifact: Return target creature card from your graveyard to your hand. Draw a card. Activate only as a sorcery.

Evolving Wilds

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Mountain

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Hazardous Blast

Hazardous Blast deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Gnawing Crescendo

Creatures you control get +2/+0 until end of turn. Whenever a nontoken creature you control dies this turn, create a 1/1 black Rat creature token with "This token can't block."

Wail of the Nim

Choose one —
• Regenerate each creature you control.
• Wail of the Nim deals 1 damage to each creature and each player.
Entwine {B} (Choose both if you pay the entwine cost.)

Totentanz, Swarm Piper

Whenever Totentanz or another nontoken creature you control dies, create a 1/1 black Rat creature token with "This token can't block."
{1}{B}: Target attacking Rat you control gains deathtouch until end of turn.