This deck is built to drain your opponents life as quickly as possible while simultaneously gaining large amounts of life. Almost all the cards combo with each other in one way or another, either through ETB effects, doubling life gain, draining as a result of lifegain, and creature death effects.
Soul Warden, Rhox Faithmender, Drana's Emissary, Zulaport Cutthroat and Kalastria Healer provide an abundant amount lifegain. Kalastria Healer, Zulaport Cutthroat and Drana's Emissary serve the double purpose of also draining my opponents life. Zulaport Cutthroat is especially useful against burn decks and decks that can produce big threats very fast, allowing me to still benefit from losing creatures.
Pillory of the Sleepless allows me to both stop threat and drain my opponents life. Path to Exile also allows me to get rid of threats that my creatures are unable to deal with. Healing Salve also serves a double purpose, with the ability to gain me life or to save a creature in a pinch. Shambling Vent is a lifelink body I can use if I ever find myself with extra mana after playing my spells for the turn.
Cliffhaven Vampire makes use of all the lifegain to drain my opponents life faster. Cliffhaven Vampire also creates an infinite combo with Exquisite Blood as an instant win-con, gaining me infinite life and dealing infinite damage to my opponent.
I have added
Kambal, Consul of Allocation
to punish my opponent's for playing anything but creatures and for some extra lifegain to keep my life total up against very aggro decks. I am also considering adding Anguished Unmaking to the sideboard in the case that I need more targeted removal.
I think the mainboard is pretty much finished (other than finding a replacement for Healing Salve), but the sideboard still needs some work. At this point, I am working on the mana-base and getting all the same versions of each card.
Any advice and tips would be greatly appreciated!