Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Barbarian Ring

{T}: Add {R}. Barbarian Ring deals 1 damage to you.
Threshold — {R}, {T}, Sacrifice Barbarian Ring: It deals 2 damage to any target. Activate only if seven or more cards are in your graveyard.

Suq'Ata Lancer

Haste
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Goblin Patrol

Echo {R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Jackal Pup

Whenever Jackal Pup is dealt damage, it deals that much damage to you.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Seal of Fire

Sacrifice Seal of Fire: It deals 2 damage to any target.

Cursed Scroll

{3}, {T}: Choose a card name, then reveal a card at random from your hand. If that card has the chosen name, Cursed Scroll deals 2 damage to any target.

Shock

Grim Lavamancer

{R}, {T}, Exile two cards from your graveyard: Grim Lavamancer deals 2 damage to any target.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Pyrokinesis

You may exile a red card from your hand rather than pay this spell's mana cost.
Pyrokinesis deals 4 damage divided as you choose among any number of target creatures.

Mountain

Sulfuric Vortex

At the beginning of each player's upkeep, Sulfuric Vortex deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Varchild's War-Riders

Cumulative upkeep—Have an opponent create a 1/1 red Survivor creature token. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Trample; rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)

Firebolt

Firebolt deals 2 damage to any target.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Shattering Pulse

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target artifact.

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.