Mountain

Carnage Gladiator

Whenever a creature blocks, that creature's controller loses 1 life.
{1}{B}{R}: Regenerate Carnage Gladiator.

Riot Piker

First strike
Riot Piker attacks each combat if able.

Exava, Rakdos Blood Witch

First strike, haste
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Each other creature you control with a +1/+1 counter on it has haste.

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Trouble

Trouble deals damage to target player equal to the number of cards in that player's hand.
Fuse (You may cast one or both halves of this card from your hand.)

Toil

Target player draws two cards and loses 2 life.
Fuse (You may cast one or both halves of this card from your hand.)

Toil // Trouble

Grim Roustabout

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
{1}{B}: Regenerate Grim Roustabout.

Spawn of Rix Maadi

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Punish the Enemy

Punish the Enemy deals 3 damage to target player or planeswalker and 3 damage to target creature.

Morgue Burst

Return target creature card from your graveyard to your hand. Morgue Burst deals damage to any target equal to the power of the card returned this way.

Minotaur Aggressor

Rakdos Guildgate

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

Rakdos Drake

Flying
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Smelt-Ward Gatekeepers

When Smelt-Ward Gatekeepers enters, if you control two or more Gates, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Slum Reaper

When Slum Reaper enters, each player sacrifices a creature of their choice.

Spike Jester

Sinister Possession

Enchant creature
Whenever enchanted creature attacks or blocks, its controller loses 2 life.

Gutter Skulk

Swamp

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice Rakdos Cluestone: Draw a card.

Bloodfray Giant

Trample
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)