Lord Skitter, Sewer King

Whenever another Rat you control enters, exile up to one target card from an opponent's graveyard.
At the beginning of combat on your turn, create a 1/1 black Rat creature token with "This creature can't block."

Foreboding Ruins

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped.
{T}: Add {B} or {R}.

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

Tinybones Joins Up

When Tinybones Joins Up enters, any number of target players each discard a card.
Whenever a legendary creature you control enters, any number of target players each mill a card and lose 1 life.

Mountain

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Deep-Cavern Bat

Flying, lifelink
When Deep-Cavern Bat enters, look at target opponent's hand. You may exile a nonland card from it until Deep-Cavern Bat leaves the battlefield.

Rattleback Apothecary

Deathtouch
Whenever you commit a crime, target creature you control gains your choice of menace or lifelink until end of turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Kaervek, the Punisher

Whenever you commit a crime, exile up to one target black card from your graveyard and copy it. You may cast the copy. If you do, you lose 2 life. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime. Copies of permanent spells become tokens.)

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Vadmir, New Blood

Whenever you commit a crime, put a +1/+1 counter on Vadmir, New Blood. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
As long as Vadmir has four or more +1/+1 counters on it, it has menace and lifelink.

Swamp

Magda, the Hoardmaster

Whenever you commit a crime, create a tapped Treasure token. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Sacrifice three Treasures: Create a 4/4 red Scorpion Dragon creature token with flying and haste. Activate only as a sorcery.

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

At Knifepoint

During your turn, outlaws you control have first strike. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Whenever you commit a crime, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery." This ability triggers only once each turn.

Servant of the Stinger

Deathtouch
Whenever Servant of the Stinger deals combat damage to a player, if you've committed a crime this turn, you may sacrifice Servant of the Stinger. If you do, search your library for a card, put it into your hand, then shuffle. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Laughing Jasper Flint

Creatures you control but don't own are Mercenaries in addition to their other types.
At the beginning of your upkeep, exile the top X cards of target opponent's library, where X is the number of outlaws you control. Until end of turn, you may cast spells from among those cards, and mana of any type can be spent to cast those spells.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Rush of Dread

Spree (Choose one or more additional costs.)
+ {1} — Target opponent sacrifices half the creatures they control of their choice, rounded up.
+ {2} — Target opponent discards half the cards in their hand, rounded up.
+ {2} — Target opponent loses half their life, rounded up.

Hopeless Nightmare

When Hopeless Nightmare enters, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Go for the Throat

Vial Smasher, Gleeful Grenadier

Whenever another outlaw you control enters, Vial Smasher, Gleeful Grenadier deals 1 damage to target opponent. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Duress

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

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.