Olivia, Crimson Bride

Flying, haste
Whenever Olivia, Crimson Bride attacks, return target creature card from your graveyard to the battlefield tapped and attacking. It gains "When you don't control a legendary Vampire, exile this creature."

Mountain

Bloodthirsty Adversary

Haste
When Bloodthirsty Adversary enters, you may pay {2}{R} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on Bloodthirsty Adversary, then exile up to that many target instant and/or sorcery cards with mana value 3 or less from your graveyard and copy them. You may cast any number of the copies without paying their mana costs.

Curse of Hospitality

Enchant player
Creatures attacking enchanted player have trample.
Whenever a creature deals combat damage to enchanted player, that player exiles the top card of their library. Until end of turn, that creature's controller may play that card and they may spend mana as though it were mana of any color to cast that spell.

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.

Smoldering Marsh

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

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

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.

Sorin the Mirthless

+1: Look at the top card of your library. You may reveal that card and put it into your hand. If you do, you lose life equal to its mana value.
−2: Create a 2/3 black Vampire creature token with flying and lifelink.
−7: Sorin the Mirthless deals 13 damage to any target. You gain 13 life.