Wild Slash

Ferocious — If you control a creature with power 4 or greater, damage can't be prevented this turn.
Wild Slash deals 2 damage to any target.

Goblin Instigator

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

Burning-Tree Emissary

When Burning-Tree Emissary enters the battlefield, add {R}{G}.

Mountain

Lightning Strike

Lightning Strike deals 3 damage to any target.

Goblin Rabblemaster

Other Goblin creatures you control attack each combat if able.
At the beginning of combat on your turn, create a 1/1 red Goblin creature token with haste.
Whenever Goblin Rabblemaster attacks, it gets +1/+0 until end of turn for each other attacking Goblin.

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 the battlefield, if its surge cost was paid, other creatures you control get +1/+0 and gain haste until end of turn.

Bomat Courier

Haste
Whenever Bomat Courier attacks, exile the top card of your library face down. (You can't look at it.)
{R}, Discard your hand, Sacrifice Bomat Courier: Put all cards exiled with Bomat Courier into their owners' hands.

Castle Embereth

Castle Embereth enters the battlefield tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Fanatical Firebrand

Haste
{T}, Sacrifice Fanatical Firebrand: It deals 1 damage to any target.

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.

Stoke the Flames

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.)
Stoke the Flames deals 4 damage to any target.

Foundry Street Denizen

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