This is not my deck idea. I found this deck in its original form . I have not made significant changes to the play style, but I couldn't find a similar build on Tapped Out, so I thought I'd upload my own slight variation. Any feedback would be appreciated.
To put it entirely bluntly, this deck is a zombie fueled blood engine. The core mechanic involves using Bloodthrone Vampire to sac Gravecrawler, triggering Blood Artist and Diregraf Captain. The fact that Gravecrawler has a hard time staying dead makes this cycle cheap, repeatable, and devastating. For added synergy, Skirsdag High Priest and Tragic Slip take wonderful advantage of all of the self-sacrifice.
I've run across a ton of builds using Blood Artist, but Diregraf Captain is a card I rarely see other people play. It lacks the universal loss/gain of its vampire counterpart, but the +1/+1 to all zombies in play should not be discounted. I've had matches where people have gone out of their way to remove Blood Artist only to be bludgeoned to death by a buffed wall of corpses.
Duskmantle Seer
by itself is a great card. It's the only thing in this deck with a CMC above 3, so the activated ability is almost guaranteed to burn your opponent more than it burns you.
Corpse Blockade
is a situational defender. It's a worse sacrifice engine than Bloodthrone Vampire but the thread of giving a wall death touch is mutually assured destruction at its finest. Since this deck thrives off of killing its own, opponents aren't generally apt to try attacking
Corpse Blockade
.
The other zombies I haven't mentioned are basically filler. Geralf's Messenger is nice because of the life loss and the undying, but absolutely no zombie can hold a candle to Gravecrawler in terms of utility.
Liliana of the Veil is a beautiful card, but it is far outside my price range.