Chandra, Awakened Inferno

This spell can't be countered.
+2: Each opponent gets an emblem with "At the beginning of your upkeep, this emblem deals 1 damage to you."
−3: Chandra, Awakened Inferno deals 3 damage to each non-Elemental creature.
−X: Chandra, Awakened Inferno deals X damage to target creature or planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Electrodominance

Electrodominance deals X damage to any target. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Mountain

Scampering Scorcher

When Scampering Scorcher enters, create two 1/1 red Elemental creature tokens. Elementals you control gain haste until end of turn. (They can attack and {T} this turn.)

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

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.

Fanatical Firebrand

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}, Sacrifice this creature: It deals 1 damage to any target.

Scorch Spitter

Whenever Scorch Spitter attacks, it deals 1 damage to the player or planeswalker it's attacking.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, Chandra's Spitfire gets +3/+0 until end of turn.

Cavalcade of Calamity

Whenever a creature you control with power 1 or less attacks, Cavalcade of Calamity deals 1 damage to the player or planeswalker that creature is attacking.

Tin Street Dodger

Haste
{R}: Tin Street Dodger can't be blocked this turn except by creatures with defender.

Shock

Thrill of Possibility

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

Goblin Smuggler

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}: Another target creature with power 2 or less can't be blocked this turn.

Smelt

This spell can't be countered.
Fry deals 5 damage to target creature or planeswalker that's white or blue.

Torch Courier

Haste
Sacrifice Torch Courier: Another target creature gains haste until end of turn.

Redcap Melee

Redcap Melee deals 4 damage to target creature or planeswalker. If a nonred permanent is dealt damage this way, you sacrifice a land.

Guttersnipe

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