Spitting Earth

Spitting Earth deals damage to target creature equal to the number of Mountains you control.

Entropic Cloud

Creatures you control gain deathtouch until end of turn. (Then exile this card. You may cast the creature later from exile.)

Topaz Dragon

Topaz Dragon // Entropic Cloud

Dragonlord Kolaghan

Flying, haste
Other creatures you control have haste.
Whenever an opponent casts a creature or planeswalker spell with the same name as a card in their graveyard, that player loses 10 life.

Goblin Spelunkers

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Assassinate

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

The Initiative

Whenever one or more creatures a player controls deal combat damage to you, that player takes the initiative.
Whenever you take the initiative and at the beginning of your upkeep, venture into Undercity. (If you're in a dungeon, advance to the next room. If you're not, enter Undercity. You can take the initiative even if you already have it.)

Undercity

You can't enter this dungeon unless you "venture into Undercity."
Secret Entrance — Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Leads to: Forge, Lost Well)
Forge — Put two +1/+1 counters on target creature. (Leads to: Trap!, Arena)
Lost Well — Scry 2. (Leads to: Arena, Stash)
Trap! — Target player loses 5 life. (Leads to: Archives)
Arena — Goad target creature. (Leads to: Archives, Catacombs)
Stash — Create a Treasure token. (Leads to: Catacombs)
Archives — Draw a card. (Leads to: Throne of the Dead Three)
Catacombs — Create a 4/1 black Skeleton creature token with menace. (Leads to: Throne of the Dead Three)
Throne of the Dead Three — Reveal the top ten cards of your library. Put a creature card from among them onto the battlefield with three +1/+1 counters on it. It gains hexproof until your next turn. Then shuffle.

Undercity // The Initiative

Skitter of Lizards

Multikicker {1}{R} (You may pay an additional {1}{R} any number of times as you cast this spell.)
Haste
Skitter of Lizards enters with a +1/+1 counter on it for each time it was kicked.

Vicious Battlerager

When Vicious Battlerager enters, you take the initiative.
Spiked Retribution — Whenever Vicious Battlerager becomes blocked by a creature, that creature's controller loses 5 life.

Swamp

Rakdos Ickspitter

{T}: Rakdos Ickspitter deals 1 damage to target creature and that creature's controller loses 1 life.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Severed Legion

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Goblin Chariot

Haste (This creature can attack and {T} as soon as it comes under your control.)

Distress

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Contaminated Bond

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature attacks or blocks, its controller loses 3 life.

Plague Beetle

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Seismic Shift

Destroy target land. Up to two target creatures can't block this turn.

Highway Robber

When Highway Robber enters, target opponent loses 2 life and you gain 2 life.

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Mind Rot

Molten Primordial

Haste
When Molten Primordial enters, for each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain haste until end of turn.

Melt Terrain

Destroy target land. Melt Terrain deals 2 damage to that land's controller.

Mountain

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Mugging

Mugging deals 2 damage to target creature. That creature can't block this turn.

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Lightning Elemental

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Fear

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Fanatical Firebrand

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}, Sacrifice this creature: It deals 1 damage to any target.