Korlash, Heir to Blackblade

Korlash's power and toughness are each equal to the number of Swamps you control.
{1}{B}: Regenerate Korlash.
Grandeur — Discard another card named Korlash, Heir to Blackblade: Search your library for up to two Swamp cards, put them onto the battlefield tapped, then shuffle.

Evernight Shade

{B}: This creature gets +1/+1 until end of turn.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Cemetery Recruitment

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Gravedigger

When this creature enters, you may return target creature card from your graveyard to your hand.

Virtus's Maneuver

For each player, choose friend or foe. Each friend returns a creature card from their graveyard to their hand. Each foe sacrifices a creature of their choice.

Darkling Stalker

{B}: Regenerate this creature.
{B}: This creature gets +1/+1 until end of turn.

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature of their choice. If you have the city's blessing, instead each opponent sacrifices half the creatures they control of their choice, rounded up.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Cabal Coffers

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

Lashwrithe

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each Swamp you control.
Equip {B/P}{B/P} ({B/P} can be paid with either {B} or 2 life.)

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the greatest mana value among creatures and planeswalkers they control.

Underworld Connections

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

Sol Ring

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Burnished Hart

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

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, all creatures get -2/-2 until end of turn.

Fendeep Summoner

{T}: Up to two target Swamps each become 3/5 Treefolk Warrior creatures in addition to their other types until end of turn.

Mirage Mirror

{2}: This artifact becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Disciple of Bolas

When this creature enters, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Staff of the Death Magus

Whenever you cast a black spell or a Swamp you control enters, you gain 1 life.

Caged Sun

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add an additional one mana of that color.

Amulet of Vigor

Whenever a permanent you control enters tapped, untap it.

Finale of Eternity

Destroy up to three target creatures with toughness X or less. If X is 10 or more, return all creature cards from your graveyard to the battlefield.

Liliana Vess

+1: Target player discards a card.
−2: Search your library for a card, then shuffle and put that card on top.
−8: Put all creature cards from all graveyards onto the battlefield under your control.

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

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}.

Mirror of the Forebears

As this artifact enters, choose a creature type.
{1}: Until end of turn, this artifact becomes a copy of target creature you control of the chosen type, except it's an artifact in addition to its other types.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

Tower of Fortunes

Phyrexian Arena

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

Defile

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

Bubbling Muck

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

Sign in Blood

Target player draws two cards and loses 2 life.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Hero's Downfall

Genju of the Fens

Enchant Swamp
{2}: Until end of turn, enchanted Swamp becomes a 2/2 black Spirit creature with "{B}: This creature gets +1/+1 until end of turn." It's still a land.
When enchanted Swamp is put into a graveyard, you may return this card from your graveyard to your hand.

Null Profusion

Skip your draw step.
Whenever you play a card, draw a card.
Your maximum hand size is two.

Journeyer's Kite

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Night's Whisper

Mask of Griselbrand

Equipped creature has flying and lifelink.
Whenever equipped creature dies, you may pay X life, where X is its power. If you do, draw X cards.
Equip {3}

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Nantuko Shade

{B}: This creature gets +1/+1 until end of turn.

Swamp

Drain Life

Spend only black mana on X.
Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.

Shade's Form

Enchant creature
Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."
When enchanted creature dies, return that card to the battlefield under your control.

Solemn Simulacrum

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

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Curse of Vengeance

Enchant player
Whenever enchanted player casts a spell, put a spite counter on this Aura.
When enchanted player loses the game, you gain X life and draw X cards, where X is the number of spite counters on this Aura.

Walking Atlas

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Blood Beckoning

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Return target creature card from your graveyard to your hand. If this spell was kicked, instead return two target creature cards from your graveyard to your hand.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When this creature dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Liliana's Shade

When this creature enters, you may search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
{B}: This creature gets +1/+1 until end of turn.

Consume Spirit

Spend only black mana on X.
Consume Spirit deals X damage to any target and you gain X life.

Geth, Lord of the Vault

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.