This is a standard vampire control deck that focuses on removing your opponent's creatures while building an army of juiced up vampires with first strike thanks to Stromkirk Captain, Captivating Vampire, and Lord of Lineage (transformed Bloodline Keeper).
The Gatekeeper of Malakir and Anowon, the Ruin Sage are great assets because they are creatures that add to the control aspect of the deck. Gatekeeper makes your opponent sacrifice a creature when it arrives on the field kicked and Anowon makes your opponent sacrifice a creature at the beginning of your every turn. Couple these guys with spells like Go for the Throat and Terminate and you got yourself some insane creature removal. Lightning Bolt is a cheap way of eliminating early threats and also becomes relevant late game to potentially deal the extra damage to finish the game. Dismember is there obviously to get rid of indestructibles and Sign in Blood is in the deck to provide some much needed draw power.
Good synergies in the deck include Stromkirk Captain with Vampire Nighthawk. Captain gives Nighthawk first strike, which combined with Nighthawk's death touch will allow Nighthawk to destroy almost any creature without afflicting harm to itself. Another good synergy is Bloodline Keeper and Captivating Vampire. Keeper helps generate the field presence, in the form of vampire tokens, necessary to activate Captivating's ability, which can be considered another type of creature removal.
Kalastria Highborn is splashed in the deck because she has good stats for a two drop vampire and comes with a very interesting ability. Every time one of your vampires dies, Kalastria will allow you to pay just one Swamp to deal two damage and also gain two life. This damage and life gain can really add up, which might make your opponent think twice about attacking when Kalastria is on the field. The life gain is really nice because Sign in Blood, Dismember, and Blood Crypt can take a toll on your life.
As a final addition to the deck, I put in one Olivia Voldaren because she can really be a menace mid to late game when you have established a large mana pool. Simply use her first ability to make a target opponent's creature a vampire and then use the second ability to steal it. You can also kill weaker foes with her by using her first ability multiple times. I know this deck is a bit creature heavy and would recommend siding out the Anowons in place of more noncreature spells if you need to emphasize control more.
