My modern Vamp deck
Bloodghast for constant pressure and control hate
Viscera Seer for helping Bloodghast dodge exile removal, and sacing things for a scry before they are killed. Works well in conjunction with Bloodghast, as dropping a land brings it back for further scry if needed. Also the scrying is useful to turn Vampire Nocturnus on when you need a black card on top of your library and all that's staring at you is a land.
And also helps to turn on Fatal Push's revolt.
Kalastria Highborn for lifegain and direct pain, punishing them for killing your creatures or using a board wipe. Combos with Viscera Seer's sacrificing ability, for smashing through some last damage. Especially when saccing Bloodghast repeatedly (can do so 3 times in a turn if Bloodghast is on the field at start of turn and you drop a Bloodstained Mire) That little combo gains you 6 life and deals 6 damage to the opponent for the cost of 3B, not to mention you get to scry 3.
Guul Draz Assassin a great mana sink for Nykthos, Shrine to Nyx in the mid game, so it's not a dead draw when top decking. When level 1 it's great for hitting a lot of Modern's weenie creatures, and when fully leveled is quite a powerful removal tool.
Gatekeeper of Malakir for turn 3 edict, what a guy!
Yahenni, Undying Partisan works well to play into blood ghasts indispensability and to grow with the kill spells and Gatekeeper of Malikir's edict. His sacrifice ability also helps turn on Fatal Push.
Vampire Nocturnus... no reason needed.
Olivia Voldaren for a growing flyer, that steals their creatures. What more could you ask for!?
She also provides a great target for all the mana that Nykthos, Shrine to Nyx generates mid game.
Blood Baron of Vizkopa great at dodging most of the removal used in modern. All black kill spells, white exile, lightning bolt. That tied to a 4/4 lifelink is solid.
Sudden Spoiling This card is the golden child of this deck!! For shutting down hexproof/indestructible/combos and acting as a mass kill card when the opponent or you block a bunch of creatures. Blocking any creature in this deck besides viscera seer when this card is cast will usually mean the blocking creatures die unless buffed at instant speed (once this card resolves) or there are passive enchantment effects helping them. A very useful card in this deck!
Also can be used to hold on one more turn as a fog effect. But this spell is put in to be used offensively in this deck.
Note that this spell cannot be countered. It's split second means once you cast it IT RESOLVES. NOTHING can be done until it resolves.
Thoughtseize and Inquisition of Kozilek for hand disruption ie stopping combos, extracting removal and key pieces of their hand and clearing a path to victory.
Go for the Throat (cannot be redirected by Spellskite) , Terminate and Fatal Push to cover the removal side of things.
Sign in Blood helps with card recovery as this deck dumps its hand rather quickly. The life drain from this and
thought seize
can take a toll but can be balanced out with Kalastria Highborn's life gain.
Nykthos, Shrine to Nyx works strongly with vampires as they have excellent devotion, often giving value turn 4
Basic Sideboard rundown
Vampire Hexmage because screw Planeswalkers, Pyromancer Ascension, and many other cards.
Torpor Orb slows some of pods interactions and can helps stop some particularly nasty ETB effects. Shuts down splintertwin and kiki jiki combos, even ruins Snapcaster Mage's day... if you're into that kinda thing.
Spellskite this little fella as we all know has a wide variety of uses. Always happy to run 1 in sideboard.
Pithing Needle can stop pod, stop kiki and splinter. Hits manlands and fetch lands, planeswalkers.
Whip of Erebos for match ups where lifegain is needed, also great for reviving Vampire Nocturnus to swing for finishing damage. Quick way to gain enough life to turn on Vizkopa's "win more" ability. Or get one last vamp to tap Captivating Vampire
Relic of Progenitus to screw over reanimator decks and Snapcaster Mage, anything really that loves graveyard. Also stops undying quite nicely for a free tap.
Cavern of Souls is perfect against control as there is only 1 creature type in this deck
Slaughter Pact is great to sideboard in against the creature combo decks, so you can always rest easy ending your turn with all mana tapped out
Stony Silence stops tron and pod decks