I think you should switch the Duress and the Inquisitions, because I think your going to like taking almost whatever you like instead of only going for noncreature nonland cards.

Intangible Virtue for your Lingering Souls tokens

That or Honor of the Pure. Will help with the non token ones too.

I would not go for either of these. A playset of Lingering Souls is not enough to justify those cards. The anthems are good when you play multiple weak creature a turn, but in here you usually play just one creature a turn and that +1/+1 bonus is therefore not that impressive.

replace duress in the sideboard with Thoughtseize, Raise the Alarm with Ghostly Prison (ghostly prison hoses on both aggro and twin, raise only really seems to help against aggro)

Thoughtseize is quite expensive though...how about Extirpate or Inquisition of Kozilek

then Duress is probably fine for the time being :P

Have you thought about adding in Crypt Ghast/Debt to the Deathless in here?

Also, you could add in the Exquisite Blood + Sanguine Bond combo.

the four of those cards are absurdly slow.

but the Exquisite Blood+Sanguine Bond is an insta-win, a finisher for this deck.

you can potentially lose two turns of tempo in a 4 turn format by running those cards. unless your deck is dedicated to running that frankly uncompetitive combo, I feel like it's not worth running either of those cards, as archangel of thune, lingering souls, and desecration demon are better finishers because of their relevance the turn they drop.

damn.. this deck is looking hella good, would +1 again if i could!

I'd suggest Night's Whisper over Sign in Blood for the maybeboard since it's not mono-black, and you're not always going to have the Tomb of Yawgmoth in play. Since you have slightly more black mana than white, I'd suggest going with Damnation over Wrath of God (assuming this isn't a budget deck). Finally, I'd suggest switching out Nyx-Fleece Ram for Wall of Souls.

Vox_: I've had Sign in Blood win matches for me in other decks before which is why this is in my maybe board. I'm not even sure if it'll make its way into the main deck because of Phyrexian Arena. As for Damnation over Wrath of God, I simply went with wrath because I own a few copies already. With Fetid Heath I really haven't ran into any issues with or casting costs. And Nyx-Fleece Ram has proven to be a solid fit in this deck.

Fair enough, just offering ideas. :)

Pillory of the Sleepless. I think that this just is good at slowing down decks that revolve around creatures. It also puts a hard cap on the length of the game when used in conert with Obzedat, Ghost Council

Norn's Annex?

cplvela0811: Looks like a fun card. I'll have to try it out.

Serra Ascendant?

jcaseys34323: Love the card, but there's not enough early life gain in the deck to support it.

With all the Terminate's and Path to Exile's floating around, might Blood Baron of Vizkopa be better than Divinity of Pride?

I agree with TClaw. As well as being easier to cast - (a t3/4/5 vault wont support divinity), BB actually just seems to be a better body.

tclaw12,Maringam: I've actually done some play testing with Blood Baron of Vizkopa and it's kinda difficult to activate his ability in this deck. I prefer Divinity of Pride because its ability is much easier to activate, and because it has flying.

Instead of Divinity of Pride you could run Baneslayer Angel.

Orzhov Pontiff? You have significant targetted hate spells, but not too much you do against an army, other than creature your own army of souls. Just a suggestion in case you run into too many opponent Lingering Souls or Empty the Warrens