Bloodcrazed Socialite

Menace
When Bloodcrazed Socialite enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever Bloodcrazed Socialite attacks, you may sacrifice a Blood token. If you do, it gets +2/+2 until end of turn.

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Swamp

Fiend of the Shadows

Flying
Whenever Fiend of the Shadows deals combat damage to a player, that player exiles a card from their hand. You may play that card for as long as it remains exiled.
Sacrifice a Human: Regenerate Fiend of the Shadows.

Bloodborn Scoundrels

Assist (Another player can pay up to {5} of this spell's cost.)
When Bloodborn Scoundrels enters, target opponent loses 2 life and you gain 2 life.

Drana's Chosen

Cohort — {T}, Tap an untapped Ally you control: Create a tapped 2/2 black Zombie creature token.

Darksteel Colossus

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Indestructible (Damage and effects that say "destroy" don't destroy this creature.)
If Darksteel Colossus would be put into a graveyard from anywhere, reveal Darksteel Colossus and shuffle it into its owner's library instead.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Bold Plagiarist

Flash
Whenever an opponent puts one or more counters on a creature they control, they put the same number and kind of counters on Bold Plagiarist.

Malakir Bloodwitch

Flying, protection from white
When Malakir Bloodwitch enters, each opponent loses life equal to the number of Vampires you control. You gain life equal to the life lost this way.

Bat Whisperer

When Bat Whisperer enters, if an opponent lost life this turn, create a 1/1 black Bat creature token with flying.

Kinzu of the Bleak Coven

Flying
Whenever another nontoken creature you control dies, you may pay 2 life and exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and has toxic 1. (Players dealt combat damage by it also get a poison counter.)

Guul Draz Overseer

Flying
Landfall — Whenever a land you control enters, other creatures you control get +1/+0 until end of turn. If that land is a Swamp, those creatures get +2/+0 until end of turn instead.

Marshland Bloodcaster

Flying
{1}{B}, {T}: Rather than pay the mana cost of the next spell you cast this turn, you may pay life equal to that spell's mana value.

Bringer of the Last Gift

Flying
When Bringer of the Last Gift enters, if you cast it, each player sacrifices all other creatures they control. Then each player returns all creature cards from their graveyard that weren't put there this way to the battlefield.

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Abolisher of Bloodlines

Flying
When this creature transforms into Abolisher of Bloodlines, target opponent sacrifices three creatures of their choice.

Voldaren Pariah

Flying
Sacrifice three other creatures: Transform Voldaren Pariah.
Madness {B}{B}{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.)

Voldaren Pariah // Abolisher of Bloodlines

Bloodtithe Collector

Flying
When this creature enters, if an opponent lost life this turn, each opponent discards a card.

Vampire Champion

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Henrika, Infernal Seer

Flying, deathtouch, lifelink
{1}{B}{B}: Each creature you control with flying, deathtouch, and/or lifelink gets +1/+0 until end of turn.

Henrika Domnathi

Flying
At the beginning of combat on your turn, choose one that hasn't been chosen —
• Each player sacrifices a creature of their choice.
• You draw a card and you lose 1 life.
• Transform Henrika Domnathi.

Henrika Domnathi // Henrika, Infernal Seer

Sengir Connoisseur

Flying
Whenever one or more other creatures die, put a +1/+1 counter on Sengir Connoisseur. This ability triggers only once each turn.

Skulking Killer

When Skulking Killer enters, target creature an opponent controls gets -2/-2 until end of turn if that opponent controls no other creatures.

Dusk Feaster

Delirium — This spell costs {2} less to cast if there are four or more card types among cards in your graveyard.
Flying

Malakir Soothsayer

Cohort — {T}, Tap an untapped Ally you control: You draw a card and you lose 1 life.

Radiant Epicure

Converge — When Radiant Epicure enters, each opponent loses X life and you gain X life, where X is the number of colors of mana spent to cast this spell.

Rabid Bloodsucker

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Rabid Bloodsucker enters, each player loses 2 life.

Thief of Blood

Flying
As Thief of Blood enters, remove all counters from all permanents. Thief of Blood enters with a +1/+1 counter on it for each counter removed this way.

Necropolis Regent

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

Vito's Inquisitor

{B}, Sacrifice another creature or artifact: Put a +1/+1 counter on Vito's Inquisitor. It gains menace until end of turn.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Drana, Kalastria Bloodchief

Flying
{X}{B}{B}: Target creature gets -0/-X until end of turn and Drana, Kalastria Bloodchief gets +X/+0 until end of turn.