Sol Ring

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Blisterspit Gremlin

{1}, {T}: Blisterspit Gremlin deals 1 damage to each opponent.
Whenever you cast a noncreature spell, untap Blisterspit Gremlin.

Tor Wauki the Younger

Reach, lifelink
If another source you control would deal noncombat damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.
Whenever you cast an instant or sorcery spell, Tor Wauki the Younger deals 2 damage to any target.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Swamp

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Rakdos Carnarium

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

Foreboding Ruins

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped.
{T}: Add {B} or {R}.

Rakdos Keyrune

{T}: Add {B} or {R}.
{B}{R}: Rakdos Keyrune becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Temple of Malice

Temple of Malice enters tapped.
When Temple of Malice enters, scry 1.
{T}: Add {B} or {R}.

Akoum Refuge

Akoum Refuge enters tapped.
When Akoum Refuge enters, you gain 1 life.
{T}: Add {B} or {R}.

Cinder Barrens

Cinder Barrens enters tapped.
{T}: Add {B} or {R}.

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice Rakdos Cluestone: Draw a card.

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Rug of Smothering

Flying
Whenever a player casts a spell, they lose 1 life for each spell they've cast this turn.

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.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Bloodfell Caves

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

Pestilent Spirit

Menace, deathtouch
Instant and sorcery spells you control have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Murder

Shock

Unlicensed Disintegration

Destroy target creature. If you control an artifact, Unlicensed Disintegration deals 3 damage to that creature's controller.

Kolaghan Monument

{T}: Add {B} or {R}.
{4}{B}{R}: Kolaghan Monument becomes a 4/4 black and red Dragon artifact creature with flying until end of turn.

Rakdos Locket

{T}: Add {B} or {R}.
{B/R}{B/R}{B/R}{B/R}, {T}, Sacrifice Rakdos Locket: Draw two cards.

Court of Ire

When Court of Ire enters, you become the monarch.
At the beginning of your upkeep, Court of Ire deals 2 damage to any target. If you're the monarch, it deals 7 damage instead.

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Bituminous Blast

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Bituminous Blast deals 4 damage to target creature.

Mountain

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, Scytheclaw Raptor deals 4 damage to them.