Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Sol Ring

Universal Automaton

Changeling (This card is every creature type.)

Insatiable Avarice

Spree (Choose one or more additional costs.)
+ {2} — Search your library for a card, then shuffle and put that card on top.
+ {B}{B} — Target player draws three cards and loses 3 life.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Songs of the Damned

Add {B} for each creature card in your graveyard.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Dark Ritual

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Mox Diamond

If Mox Diamond would enter the battlefield, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.