Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

Piper of the Swarm

Rats you control have menace.
{1}{B}, {T}: Create a 1/1 black Rat creature token.
{2}{B}{B}, {T}, Sacrifice three Rats: Gain control of target creature.

Star Compass

This artifact enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Swamp

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Leaden Myr

Relentless Rats

This creature gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Marrow-Gnawer

All Rats have fear.
{T}, Sacrifice a Rat: Create X 1/1 black Rat creature tokens, where X is the number of Rats you control.

Jet Medallion

Black spells you cast cost {1} less to cast.

Demonic Tutor

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)