Mask of Avacyn

Equipped creature gets +1/+2 and has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {3}

Arena Athlete

Heroic — Whenever you cast a spell that targets Arena Athlete, target creature an opponent controls can't block this turn.

Siege-Gang Commander

When Siege-Gang Commander enters the battlefield, create three 1/1 red Goblin creature tokens.
{1}{R}, Sacrifice a Goblin: Siege-Gang Commander deals 2 damage to any target.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Clamor Shaman

Riot (This creature enters the battlefield with your choice of a +1/+1 counter or haste.)
Whenever Clamor Shaman attacks, target creature an opponent controls can't block this turn.

Beetleback Chief

When Beetleback Chief enters the battlefield, create two 1/1 red Goblin creature tokens.

Legion Warboss

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

Masterwork of Ingenuity

You may have Masterwork of Ingenuity enter the battlefield as a copy of any Equipment on the battlefield.

Ardent Elementalist

When Ardent Elementalist enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Toggo, Goblin Weaponsmith

Landfall — Whenever a land enters the battlefield under your control, create a colorless Equipment artifact token named Rock with "Equipped creature has '{1}, {T}, Sacrifice Rock: This creature deals 2 damage to any target'" and equip {1}.
Partner (You can have two commanders if both have partner.)

Past in Flames

Each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Unleash Fury

Double the power of target creature until end of turn.

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn.

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Shreds of Sanity

Return up to one target instant card and up to one target sorcery card from your graveyard to your hand, then discard a card. Exile Shreds of Sanity.

Goblin War Party

Choose one —
• Create three 1/1 red Goblin creature tokens.
• Creatures you control get +1/+1 and gain haste until end of turn.
Entwine {2}{R} (Choose both if you pay the entwine cost.)

Goblin Rally

Create four 1/1 red Goblin creature tokens.

Song of Totentanz

Create X 1/1 black Rat creature tokens with "This creature can't block." Creatures you control gain haste until end of turn.

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.)

Caterwauling Boggart

Goblins you control and Elementals you control have menace. (They can't be blocked except by two or more creatures.)

Valduk, Keeper of the Flame

At the beginning of combat on your turn, for each Aura and Equipment attached to Valduk, Keeper of the Flame, create a 3/1 red Elemental creature token with trample and haste. Exile those tokens at the beginning of the next end step.

Mountain

Foundry Street Denizen

Whenever another red creature enters the battlefield under your control, Foundry Street Denizen gets +1/+0 until end of turn.

Grab the Reins

Choose one —
• Until end of turn, you gain control of target creature and it gains haste.
• Sacrifice a creature. Grab the Reins deals damage equal to that creature's power to any target.
Entwine {2}{R} (Choose both if you pay the entwine cost.)

Brute Force

Target creature gets +3/+3 until end of turn.

Arcane Signet

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

Antagonize

Target creature gets +4/+3 until end of turn.

Empty the Warrens

Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Living Lightning

When Living Lightning dies, return target instant or sorcery card from your graveyard to your hand.

Crimson Wisps

Target creature becomes red and gains haste until end of turn.
Draw a card.

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.

Balduvian Rage

Target attacking creature gets +X/+0 until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Immolating Gyre

Immolating Gyre deals X damage to each creature and planeswalker you don't control, where X is the number of instant and sorcery cards in your graveyard.

Guttersnipe

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

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Infuriate

Target creature gets +3/+2 until end of turn.

Young Pyromancer

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

Twinferno

Choose one —
• When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn.

Goblin Instigator

When Goblin Instigator enters the battlefield, create a 1/1 red Goblin creature token.

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.

Cheering Fanatic

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

Akroan Line Breaker

Heroic — Whenever you cast a spell that targets Akroan Line Breaker, Akroan Line Breaker gets +2/+0 and gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Run Amok

Target attacking creature gets +3/+3 and gains trample until end of turn.

Barge In

Target attacking creature gets +2/+2 until end of turn. Each attacking non-Human creature gains trample until end of turn.

Dynacharge

Target creature you control gets +2/+0 until end of turn.
Overload {2}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Sol Ring

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Goblin Matron

When Goblin Matron enters the battlefield, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Raze the Effigy

Choose one —
• Destroy target artifact.
• Target attacking creature gets +2/+2 until end of turn.

Konda's Banner

Konda's Banner can be attached only to a legendary creature.
Creatures that share a color with equipped creature get +1/+1.
Creatures that share a creature type with equipped creature get +1/+1.
Equip {2}

Ruby Medallion

Red spells you cast cost {1} less to cast.

Battle-Scarred Goblin

Whenever Battle-Scarred Goblin becomes blocked, it deals 1 damage to each creature blocking it.

Briber's Purse

Briber's Purse enters the battlefield with X gem counters on it.
{1}, {T}, Remove a gem counter from Briber's Purse: Target creature can't attack or block this turn.

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Battle Hymn

Sure Strike

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

Mirran Banesplitter

Flash
When Mirran Banesplitter enters the battlefield, attach it to target creature you control.
Equipped creature gets +2/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Burning Sun's Fury

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Up to two target creatures each get +2/+0 and gain haste until end of turn.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Kyren Flamewright

{2}{R}, {T}, Discard a card: Create two 1/1 blue and red Elemental creature tokens. Creatures you control get +1/+0 and gain haste until end of turn.

Invasion of Mercadia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Mercadia enters the battlefield, you may discard a card. If you do, draw two cards.

Invasion of Mercadia // Kyren Flamewright

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Bladegraft Aspirant

Menace
Equipment spells you cast cost {1} less to cast.
Activated abilities of Equipment you control that target Bladegraft Aspirant cost {1} less to activate.

Ral's Reinforcements

Create two 1/1 blue and red Elemental creature tokens.

Gleeful Demolition

Destroy target artifact. If you controlled that artifact, create three 1/1 red Phyrexian Goblin creature tokens.

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Ghitu Chronicler

Kicker {3}{R} (You may pay an additional {3}{R} as you cast this spell.)
When Ghitu Chronicler enters the battlefield, if it was kicked, return target instant or sorcery card from your graveyard to your hand.