Mounted Dreadknight

Trample
Mounted Dreadknight enters with a +1/+1 counter on it if an opponent lost life this turn.

Voldaren Ambusher

When Voldaren Ambusher enters, if an opponent lost life this turn, it deals X damage to up to one target creature or planeswalker, where X is the number of Vampires you control.

Hungry for More

Create a 3/1 black and red Vampire creature token with trample, lifelink, and haste. Sacrifice it at the beginning of the next end step.
Flashback {1}{B}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Arrogant Outlaw

When Arrogant Outlaw enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

Famished Foragers

When Famished Foragers enters, if an opponent lost life this turn, add {R}{R}{R}.
{2}{R}, Discard a card: Draw a card.

Bat Whisperer

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

Bloodtithe Collector

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

Voldaren Stinger

Voldaren Stinger has first strike as long as it's attacking.
{2}{R}: Voldaren Stinger gets +2/+0 until end of turn.

Swamp

Falkenrath Perforator

Whenever Falkenrath Perforator attacks, it deals 1 damage to defending player.

Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Mountain

Vampire Interloper

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.

Stromkirk Bloodthief

At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on target Vampire you control.