Underworld Connections

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

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Swamp

Butcher of Malakir

Flying
Whenever this creature or another creature you control dies, each opponent sacrifices a creature of their choice.

Patron of the Vein

Flying
When this creature enters, destroy target creature an opponent controls.
Whenever a creature an opponent controls dies, exile it and put a +1/+1 counter on each Vampire you control.

Anje, Maid of Dishonor

Whenever Anje and/or one or more other Vampires you control enter, create a Blood token. This ability triggers only once each turn. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 life.

Mountain

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Vampires' Vengeance

Vampires' Vengeance deals 2 damage to each non-Vampire creature. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Laurine, the Diversion

Partner with Kamber, the Plunderer (When this creature enters, target player may put Kamber into their hand from their library, then shuffle.)
First strike
{2}, Sacrifice an artifact or creature: Goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Sol Ring

Kamber, the Plunderer

Partner with Laurine, the Diversion (When this creature enters, target player may put Laurine into their hand from their library, then shuffle.)
Lifelink
Whenever a creature an opponent controls dies, you gain 1 life and create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Florian, Voldaren Scion

First strike
At the beginning of each of your postcombat main phases, look at the top X cards of your library, where X is the total amount of life your opponents lost this turn. Exile one of those cards and put the rest on the bottom of your library in a random order. You may play the exiled card this turn.

Bloodvial Purveyor

Flying, trample
Whenever an opponent casts a spell, that player creates a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever this creature attacks, it gets +1/+0 until end of turn for each Blood token defending player controls.

Edgar's Awakening

Return target creature card from your graveyard to the battlefield.
When you discard this card, you may pay {B}. When you do, return target creature card from your graveyard to your hand.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Sinister Waltz

Choose three target creature cards in your graveyard. Return two of them at random to the battlefield and put the other on the bottom of your library.

Crossway Troublemakers

Attacking Vampires you control have deathtouch and lifelink. (Any amount of damage they deal to a creature is enough to destroy it. Damage dealt by those creatures also causes their controller to gain that much life.)
Whenever a Vampire you control dies, you may pay 2 life. If you do, draw a card.

Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Wedding Security

Whenever this creature attacks, you may sacrifice a Blood token. If you do, put a +1/+1 counter on this creature and draw a card.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Vampire Socialite

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, if an opponent lost life this turn, put a +1/+1 counter on each other Vampire you control.
As long as an opponent lost life this turn, each other Vampire you control enters with an additional +1/+1 counter on it.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Champion of Dusk

When this creature enters, you draw X cards and you lose X life, where X is the number of Vampires you control.

Infernal Grasp

Destroy target creature. You lose 2 life.

Ivora, Insatiable Heir

Trample
When Ivora enters and whenever it deals combat damage to a player, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever you discard a card, put a +1/+1 counter on Ivora.

Midnight Arsonist

When this creature enters, destroy up to X target artifacts without mana abilities, where X is the number of Vampires you control.

Terminate

Destroy target creature. It can't be regenerated.

Blood Artist

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

Nighthawk Scavenger

Flying, deathtouch, lifelink
Nighthawk Scavenger's power is equal to 1 plus the number of card types among cards in your opponents' graveyards.

Urge to Feed

Target creature gets -3/-3 until end of turn. You may tap any number of untapped Vampire creatures you control. If you do, put a +1/+1 counter on each of those Vampires.

Necropolis Regent

Flying
Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Markov Enforcer

Whenever this creature or another Vampire you control enters, this creature fights up to one target creature an opponent controls.
Whenever a creature dealt damage by this creature this turn dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Sanctum Seeker

Whenever a Vampire you control attacks, each opponent loses 1 life and you gain 1 life.

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Rakish Heir

Whenever a Vampire you control deals combat damage to a player, put a +1/+1 counter on it.

Gluttonous Guest

When this creature enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Blood token, you gain 1 life.

Bloodsworn Steward

Flying
Commander creatures you control get +2/+2 and have haste.

Command Tower

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

Olivia's Attendants

Menace
Whenever this creature deals damage, create that many Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{2}{R}: This creature deals 1 damage to any target.

Moonstone Eulogist

Flying
Whenever a creature an opponent controls dies, you create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on this creature and you gain 1 life.

Strefan, Maurer Progenitor

Flying
At the beginning of your end step, create a Blood token for each player who lost life this turn.
Whenever Strefan attacks, you may sacrifice two Blood tokens. If you do, you may put a Vampire card from your hand onto the battlefield tapped and attacking. It gains indestructible until end of turn.

Commander's Sphere

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

Zagras, Thief of Heartbeats

This spell costs {1} less to cast for each creature in your party.
Flying, deathtouch, haste
Other creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a planeswalker, destroy that planeswalker.

Falkenrath Gorger

Each Vampire creature card you own that isn't on the battlefield has madness. The madness cost is equal to its mana cost. (If you discard a card with madness, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Cordial Vampire

Whenever this creature or another creature dies, put a +1/+1 counter on each Vampire you control.

Stensia Masquerade

Attacking creatures you control have first strike.
Whenever a Vampire you control deals combat damage to a player, put a +1/+1 counter on it.
Madness {2}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Timothar, Baron of Bats

Ward—Discard a card.
Whenever another nontoken Vampire you control dies, you may pay {1} and exile it. If you do, create a 1/1 black Bat creature token with flying. It gains "When this token deals combat damage to a player, sacrifice it and return the exiled card to the battlefield tapped."

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Pointed Discussion

You draw two cards, lose 2 life, then create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Arcane Signet

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Rakdos Signet

Glass-Cast Heart

Whenever one or more Vampires you control attack, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{B}, {T}, Pay 1 life: Create a 1/1 white and black Vampire creature token with lifelink.
{B}{B}, {T}, Sacrifice this artifact and thirteen Blood tokens: Each opponent loses 13 life and you gain 13 life.

Arterial Alchemy

When this enchantment enters, create a Blood token for each opponent you have. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Blood tokens you control are Equipment in addition to their other types and have "Equipped creature gets +2/+0" and equip {2}.

Leechridden Swamp

({T}: Add {B}.)
This land enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Captivating Vampire

Other Vampire creatures you control get +1/+1.
Tap five untapped Vampires you control: Gain control of target creature. It becomes a Vampire in addition to its other types.

Canyon Slough

({T}: Add {B} or {R}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Olivia's Wrath

Each non-Vampire creature gets -X/-X until end of turn, where X is the number of Vampires you control.

Fellwar Stone

Queen's Bay Paladin

Whenever this creature enters or attacks, return up to one target Vampire card from your graveyard to the battlefield with a finality counter on it. You lose life equal to its mana value. (If a creature with a finality counter on it would die, exile it instead.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Bloodlord of Vaasgoth

Bloodthirst 3 (If an opponent was dealt damage this turn, this creature enters with three +1/+1 counters on it.)
Flying
Whenever you cast a Vampire creature spell, it gains bloodthirst 3.

Scion of Opulence

Whenever this creature or another nontoken Vampire you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
{R}, Sacrifice two artifacts: Exile the top card of your library. You may play that card this turn.

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Blood Fountain

When this artifact enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{3}{B}, {T}, Sacrifice this artifact: Return up to two target creature cards from your graveyard to your hand.

Stromkirk Captain

First strike
Other Vampire creatures you control get +1/+1 and have first strike.

Night's Whisper

Markov Baron

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Lifelink
Other Vampires you control get +1/+1.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Bloodtithe Harvester

When this creature enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{T}, Sacrifice this creature: Target creature gets -X/-X until end of turn, where X is twice the number of Blood tokens you control. Activate only as a sorcery.

Oni-Cult Anvil

Whenever one or more artifacts you control leave the battlefield during your turn, create a 1/1 colorless Construct artifact creature token. This ability triggers only once each turn.
{T}, Sacrifice an artifact: This artifact deals 1 damage to each opponent. You gain 1 life.

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.