Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Mountain

Terror of Mount Velus

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Fateful End

Fateful End deals 3 damage to any target. Scry 1.

Lightning Blast

Lightning Blast deals 4 damage to any target.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Storm's Wrath

Storm's Wrath deals 4 damage to each creature and each planeswalker.

Iroas's Blessing

Enchant creature you control
When Iroas's Blessing enters, it deals 4 damage to target creature or planeswalker an opponent controls.
Enchanted creature gets +1/+1.

Omen of the Forge

Flash
When Omen of the Forge enters, it deals 2 damage to any target.
{2}{R}, Sacrifice Omen of the Forge: Scry 2.

Toralf's Hammer

Equipped creature has "{1}{R}, {T}, Unattach Toralf's Hammer: It deals 3 damage to any target. Return Toralf's Hammer to its owner's hand."
Equipped creature gets +3/+0 as long as it's legendary.
Equip {1}{R}

Toralf, God of Fury

Trample
Whenever a creature or planeswalker an opponent controls is dealt excess noncombat damage, Toralf deals damage equal to the excess to any target other than that permanent.

Toralf, God of Fury // Toralf's Hammer

Lightning Cloud

Whenever a player casts a red spell, you may pay {R}. If you do, Lightning Cloud deals 1 damage to any target.

Impending Doom

Enchant creature
Enchanted creature gets +3/+3 and attacks each combat if able.
When enchanted creature dies, Impending Doom deals 3 damage to that creature's controller.

Irreverent Revelers

When Irreverent Revelers enters, choose one —
• Destroy target artifact.
• Irreverent Revelers gains haste until end of turn.

Thrill of Possibility

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

Final Flare

As an additional cost to cast this spell, sacrifice a creature or enchantment.
Final Flare deals 5 damage to target creature.