Magmatic Sinkhole

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Magmatic Sinkhole deals 5 damage to target creature or planeswalker.

Goblin Instigator

When this creature enters, create a 1/1 red Goblin creature token.

Blighted Gorge

{T}: Add {C}.
{4}{R}, {T}, Sacrifice this land: It deals 2 damage to any target.

Goblin Caves

Enchant land
As long as enchanted land is a basic Mountain, Goblin creatures get +0/+2.

Battle Squadron

Flying
Battle Squadron's power and toughness are each equal to the number of creatures you control.

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Twinshot Sniper

Reach
When this creature enters, it deals 2 damage to any target.
Channel — {1}{R}, Discard this card: It deals 2 damage to any target.

Goblin Burrows

{T}: Add {C}.
{1}{R}, {T}: Target Goblin creature gets +2/+0 until end of turn.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Brute Force

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

Outpost Siege

As this enchantment enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, this enchantment deals 1 damage to any target.

Mountain

Boggart Brute

Menace (This creature can't be blocked except by two or more creatures.)

Fissure Wizard

When this creature enters, you may discard a card. If you do, draw a card.

Horde of Boggarts

Menace (This creature can't be blocked except by two or more creatures.)
Horde of Boggarts's power and toughness are each equal to the number of red permanents you control.