Twin Bolt

Twin Bolt deals 2 damage divided as you choose among one or two targets.

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Cone of Flame

Cone of Flame deals 1 damage to any target, 2 damage to another target, and 3 damage to a third target.

Pack Rat

Pack Rat's power and toughness are each equal to the number of Rats you control.
{2}{B}, Discard a card: Create a token that's a copy of Pack Rat.

Mountain

Searing Spear

Searing Spear deals 3 damage to any target.

Untamed Hunger

Enchant creature
Enchanted creature gets +2/+1 and has menace. (It can't be blocked except by two or more creatures.)

Rush of Vitality

Target creature gets +1/+0 and gains lifelink and indestructible until end of turn. (Damage dealt by that creature also causes its controller to gain that much life, and it can't be destroyed by damage or effects that say "destroy.")

Thriving Rats

When Thriving Rats enters, you get {E}{E} (two energy counters).
Whenever Thriving Rats attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Sparkmage's Gambit

Sparkmage's Gambit deals 1 damage to each of up to two target creatures. Those creatures can't block this turn.

Riddle of Lightning

Choose any target. Scry 3, then reveal the top card of your library. Riddle of Lightning deals damage equal to that card's mana value to that permanent or player.

Terror of the Fairgrounds

Outnumber

Outnumber deals damage to target creature equal to the number of creatures you control.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Impact Tremors

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

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Mind Rot

Thunderbreak Regent

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, Thunderbreak Regent deals 3 damage to that player.

Borderland Marauder

Whenever Borderland Marauder attacks, it gets +2/+0 until end of turn.

Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

Glassblower's Puzzleknot

When Glassblower's Puzzleknot enters, scry 2, then you get {E}{E}. (You get two energy counters. 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.)
{2}{U}, Sacrifice Glassblower's Puzzleknot: Scry 2, then you get {E}{E}.

Dutiful Return

Return up to two target creature cards from your graveyard to your hand.

Pyre Hound

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Pyre Hound.

Bloodfire Expert

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Wildfire Cerberus

{5}{R}{R}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)
When Wildfire Cerberus becomes monstrous, it deals 2 damage to each opponent and each creature they control.

Murder

Cinder Hellion

Trample
When Cinder Hellion enters, it deals 2 damage to target opponent or planeswalker.

Spark Jolt

Spark Jolt deals 1 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.