Retreat to Hagra

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Dark Ritual

Defile

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

Explorer's Scope

Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Walking Atlas

{T}: You may put a land card from your hand onto the battlefield.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Dread Presence

Whenever a Swamp enters the battlefield under your control, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Swamp

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Ravenous Chupacabra

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

Sign in Blood

Target player draws two cards and loses 2 life.

Geyserfield Stalker

Menace (This creature can't be blocked except by two or more creatures.)
Landfall — Whenever a land enters the battlefield under your control, Geyserfield Stalker gets +2/+2 until end of turn.

Cruel Edict

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Plaguecrafter

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Gutterbones

Gutterbones enters the battlefield tapped.
{1}{B}: Return Gutterbones from your graveyard to your hand. Activate only during your turn and only if an opponent lost life this turn.

Diabolic Edict

Star Compass

Star Compass enters the battlefield tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Ruinous Path

Destroy target creature or planeswalker.
Awaken 4—{5}{B}{B} (If you cast this spell for {5}{B}{B}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Malicious Affliction

Morbid — When you cast this spell, if a creature died this turn, you may copy Malicious Affliction and may choose a new target for the copy.
Destroy target nonblack creature.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

Ob Nixilis, the Fallen

Landfall — Whenever a land enters the battlefield under your control, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.

Caustic Crawler

Landfall — Whenever a land enters the battlefield under your control, you may have target creature get -1/-1 until end of turn.

Cast Down

Bontu's Last Reckoning

Destroy all creatures. Lands you control don't untap during your next untap step.

Walk the Plank

Ambition's Cost

You draw three cards and you lose 3 life.

The Eldest Reborn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Grave Titan

Deathtouch
Whenever Grave Titan enters the battlefield or attacks, create two 2/2 black Zombie creature tokens.

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

Paralyze

Enchant creature
When Paralyze enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {4}. If the player does, untap the creature.

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.

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Oblivion Sower

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

Charcoal Diamond

Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.

Liliana's Shade

When Liliana's Shade enters the battlefield, you may search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
{B}: Liliana's Shade gets +1/+1 until end of turn.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Cruel Reality

Enchant player
At the beginning of enchanted player's upkeep, that player sacrifices a creature or planeswalker. If the player can't, they lose 5 life.

Murder

Surrakar Marauder

Landfall — Whenever a land enters the battlefield under your control, Surrakar Marauder gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Reign of the Pit

Each player sacrifices a creature. Create an X/X black Demon creature token with flying, where X is the total power of the creatures sacrificed this way.

Adventuring Gear

Landfall — Whenever a land enters the battlefield under your control, equipped creature gets +2/+2 until end of turn.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Sol Ring

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Ghirapur Orrery

Each player may play an additional land on each of their turns.
At the beginning of each player's upkeep, if that player has no cards in hand, that player draws three cards.

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Hagra Crocodile

Hagra Crocodile can't block.
Landfall — Whenever a land enters the battlefield under your control, Hagra Crocodile gets +2/+2 until end of turn.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.