Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Mox Amber

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

Memnite

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Dark Ritual

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}.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Swamp

Dark Sphere

{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Sol Ring

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.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Spellbook

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Jeweled Lotus

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

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.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Ancient Tomb

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

Grim Monolith

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

Blood Pet

Glacial Chasm

Cumulative upkeep—Pay 2 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Glacial Chasm enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Phyrexian Walker

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}.

Sickening Dreams

As an additional cost to cast this spell, discard X cards.
Sickening Dreams deals X damage to each creature and each player.

Cabal Ritual

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

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Ornithopter

Mox Tantalite

Suspend 3—{0} (Rather than cast this card from your hand, pay {0} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}: Add one mana of any color.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Lotus Bloom

Suspend 3—{0} (Rather than cast this card from your hand, pay {0} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}, Sacrifice Lotus Bloom: Add three mana of any one color.