Have

Vaultbreaker

Whenever Vaultbreaker attacks, you may discard a card. If you do, draw a card.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Shredded Sails

Choose one —
• Destroy target artifact.
• Shredded Sails deals 4 damage to target creature with flying.
Cycling {2} ({2}, Discard this card: Draw a card.)

Grim Initiate

First strike
When Grim Initiate dies, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Getting

Rockslide Elemental

First strike
Whenever another creature dies, you may put a +1/+1 counter on Rockslide Elemental.

Thriving Grubs

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

Goblin Oriflamme

Attacking creatures you control get +1/+0.

Firecat Blitz

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.
Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Don't Have

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.)

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Generator Servant

{T}, Sacrifice Generator Servant: Add {C}{C}. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and {T} as soon as it comes under your control.)

Thrill of Possibility

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

Goblin Wardriver

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)

Firefist Striker

Battalion — Whenever Firefist Striker and at least two other creatures attack, target creature can't block this turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Cunning Sparkmage

Haste
{T}: Cunning Sparkmage deals 1 damage to any target.

Inferno

Inferno deals 6 damage to each creature and each player.

Cheering Fanatic

Whenever Cheering Fanatic attacks, choose a card name. Spells with the chosen name cost {1} less to cast this turn.

Dreamshaper Shaman

At the beginning of your end step, you may pay {2}{R} and sacrifice a nonland permanent. If you do, reveal cards from the top of your library until you reveal a nonland permanent card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Monastery Swiftspear

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

Heartfire

As an additional cost to cast this spell, sacrifice a creature or planeswalker.
Heartfire deals 4 damage to any target.

Mark of Fury

Enchant creature
Enchanted creature has haste.
At the beginning of the end step, return Mark of Fury to its owner's hand.

Sanctuary Smasher

First strike
Cycling {2}{R} ({2}{R}, Discard this card: Draw a card.)
When you cycle Sanctuary Smasher, put a first strike counter on target creature you control.

Flametongue Kavu

When Flametongue Kavu enters, it deals 4 damage to target creature.

Slaying Fire

Slaying Fire deals 3 damage to any target.
Adamant — If at least three red mana was spent to cast this spell, it deals 4 damage instead.

Bloodfray Giant

Trample
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Charging Tuskodon

Trample
If Charging Tuskodon would deal combat damage to a player, it deals double that damage to that player instead.

Fireblade Charger

As long as Fireblade Charger is equipped, it has haste.
When Fireblade Charger dies, it deals damage equal to its power to any target.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Anax, Hardened in the Forge

Anax's power is equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
Whenever Anax or another nontoken creature you control dies, create a 1/1 red Satyr creature token with "This creature can't block." If the creature had power 4 or greater, create two of those tokens instead.

Conduit of Emrakul

Whenever Conduit of Emrakul attacks, add {C}{C} at the beginning of your next main phase this turn.

Conduit of Storms

Whenever Conduit of Storms attacks, add {R} at the beginning of your next main phase this turn.
{3}{R}{R}: Transform Conduit of Storms.

Conduit of Storms // Conduit of Emrakul

Battle Display

Destroy target artifact. (Then exile this card. You may cast the creature later from exile.)

Embereth Shieldbreaker

Embereth Shieldbreaker // Battle Display

Careless Celebrant

When Careless Celebrant dies, it deals 2 damage to target creature or planeswalker an opponent controls.

Volcanic Dragon

Genju of the Spires

Enchant Mountain
{2}: Enchanted Mountain becomes a 6/1 red Spirit creature until end of turn. It's still a land.
When enchanted Mountain is put into a graveyard, you may return Genju of the Spires from your graveyard to your hand.

Charging Monstrosaur

Rubblebelt Recluse

Rubblebelt Recluse attacks each combat if able.

Forbidden Friendship

Create a 1/1 red Dinosaur creature token with haste and a 1/1 white Human Soldier creature token.

Havoc Jester

Whenever you sacrifice a permanent, Havoc Jester deals 1 damage to any target.

Goblin Cratermaker

{1}, Sacrifice Goblin Cratermaker: Choose one —
• Goblin Cratermaker deals 2 damage to target creature.
• Destroy target colorless nonland permanent.

Ahn-Crop Crasher

Haste
You may exert Ahn-Crop Crasher as it attacks. When you do, target creature can't block this turn. (An exerted creature won't untap during your next untap step.)

Sure Strike

Target creature gets +3/+0 and gains first strike until end of turn.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Spellgorger Weird

Whenever you cast a noncreature spell, put a +1/+1 counter on Spellgorger Weird.

Kazuul's Cliffs

Kazuul's Cliffs enters tapped.
{T}: Add {R}.

Kazuul's Fury

As an additional cost to cast this spell, sacrifice a creature.
Kazuul's Fury deals damage equal to the sacrificed creature's power to any target.

Kazuul's Fury // Kazuul's Cliffs

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.

Goblin Wizardry

Create two 1/1 red Goblin Wizard creature tokens with prowess. (Whenever you cast a noncreature spell, they get +1/+1 until end of turn.)

Neck Breaker

Attacking creatures you control get +1/+0 and have trample.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Neck Breaker.

Breakneck Rider

At the beginning of each upkeep, if no spells were cast last turn, transform Breakneck Rider.

Breakneck Rider // Neck Breaker

Emberhorn Minotaur

You may exert Emberhorn Minotaur as it attacks. When you do, it gets +1/+1 and gains menace until end of turn. (An exerted creature won't untap during your next untap step.)