Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Fire Diamond

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

Rakdos Signet

Asmoranomardicadaistinaculdacar

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell.
When Asmoranomardicadaistinaculdacar enters, you may search your library for a card named The Underworld Cookbook, reveal it, put it into your hand, then shuffle.
Sacrifice two Foods: Target creature deals 6 damage to itself.

Feed the Swarm

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

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Bedevil

Destroy target artifact, creature, or planeswalker.

Damnation

Destroy all creatures. They can't be regenerated.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Sol Ring

Command Tower

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

Arcane Signet

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Smoldering Marsh

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

Charcoal Diamond

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

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.