Void Mirror

Whenever a player casts a spell, if no colored mana was spent to cast it, counter that spell.

Legion Loyalist

Haste
Battalion — Whenever Legion Loyalist and at least two other creatures attack, creatures you control gain first strike and trample until end of turn and can't be blocked by creature tokens this turn.

Goblin Piledriver

Protection from blue (This creature can't be blocked, targeted, dealt damage, or enchanted by anything blue.)
Whenever Goblin Piledriver attacks, it gets +2/+0 until end of turn for each other attacking Goblin.

Ratchet Bomb

{T}: Put a charge counter on Ratchet Bomb.
{T}, Sacrifice Ratchet Bomb: Destroy each nonland permanent with mana value equal to the number of charge counters on Ratchet Bomb.

Mogg War Marshal

Echo {1}{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.)
When Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Goblin Chainwhirler

First strike
When Goblin Chainwhirler enters, it deals 1 damage to each opponent and each creature and planeswalker they control.

Blood Moon

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Smash to Smithereens

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Reckless Bushwhacker

Surge {1}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Haste
When Reckless Bushwhacker enters, if its surge cost was paid, other creatures you control get +1/+0 and gain haste until end of turn.

Mountain

Goblin Guide

Haste
Whenever Goblin Guide attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Foundry Street Denizen

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

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Mogg Fanatic

Sacrifice Mogg Fanatic: It deals 1 damage to any target.

Battle Cry Goblin

{1}{R}: Goblins you control get +1/+0 and gain haste until end of turn.
Whenever Battle Cry Goblin attacks, if you attacked with creatures with total power 6 or greater this combat, create a 1/1 red Goblin creature token that's tapped and attacking.

Cleansing Wildfire

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
Draw a card.

Goblin Bushwhacker

Kicker {R} (You may pay an additional {R} as you cast this spell.)
When this creature enters, if it was kicked, creatures you control get +1/+0 and gain haste until end of turn.