Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

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}.

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Mox Diamond

If Mox Diamond would enter, 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.

Mox Amber

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

Lion's Eye Diamond

Discard your hand, Sacrifice Lion's Eye Diamond: Add three mana of any one color. Activate only as an instant.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Imperial Seal

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

Homeward Path

{T}: Add {C}.
{T}: Each player gains control of all creatures they own.

Grim Monolith

Grim Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{4}: Untap Grim Monolith.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Shallow Grave

Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.