Urborg, Tomb of Yawgmoth

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

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Blackcleave Cliffs

Blackcleave Cliffs enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Asylum Visitor

At the beginning of each player's upkeep, if that player has no cards in hand, you draw a card and you lose 1 life.
Madness {1}{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.)

Dusk Legion Duelist

Vigilance
Whenever one or more +1/+1 counters are put on Dusk Legion Duelist, draw a card. This ability triggers only once each turn.

Ratchet Bomb

{T}: Put a charge counter on Ratchet Bomb.
{T}, Sacrifice Ratchet Bomb: Destroy each nonland permanent with mana value equal to the number of charge counters on Ratchet Bomb.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Vampire Socialite

Menace (This creature can't be blocked except by two or more creatures.)
When Vampire Socialite 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.

Voldaren Estate

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a Vampire spell.
{5}, {T}: Create a Blood token. This ability costs {1} less to activate for each Vampire you control. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Vampire of the Dire Moon

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Legion Lieutenant

Tormod's Crypt

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

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Knight of the Ebon Legion

{2}{B}: Knight of the Ebon Legion gets +3/+3 and gains deathtouch until end of turn.
At the beginning of your end step, if a player lost 4 or more life this turn, put a +1/+1 counter on Knight of the Ebon Legion. (Damage causes loss of life.)

Fragmentize

Destroy target artifact or enchantment with mana value 4 or less.

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.

Concealed Courtyard

Concealed Courtyard enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

Helping Hand

Return target creature card with mana value 3 or less from your graveyard to the battlefield tapped.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Bloodchief's Thirst

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Destroy target creature or planeswalker with mana value 2 or less. If this spell was kicked, instead destroy target creature or planeswalker.

Falkenrath Pit Fighter

{1}{R}, Discard a card, Sacrifice a Vampire: Draw two cards. Activate only if an opponent lost life this turn.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

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.)

Kolaghan's Command

Choose two —
• Return target creature card from your graveyard to your hand.
• Target player discards a card.
• Destroy target artifact.
• Kolaghan's Command deals 2 damage to any target.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

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 artifact: Draw a card.")

Gifted Aetherborn

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.