Try Blood Baron of Vizkopa . Its a great card.

@NeelBudget. Nice try though :) .

What about anything with the Extort mechanic?

What about it? Extort is not a human mechanic, so I cut it. Don't need it anyways, the deck is powerful enough as is.

Here's a few ideas for you:

Imposing Sovereign : Could be a good sideboard option against aggro.

Banisher Priest : More removal, and a human body to boot.

Cartel Aristocrat : Block their bomb by saccing a human, why not?

Fiendslayer Paladin : Aggressive, powerful, and gives you back some of the life you lose from your card draw.

Mogis's Marauder : Combos quite well with Immortal Servitude .

Best of luck to you!

Thanks for your input.Few comments/questions on your suggestions.1. Imposing Sovereign : Excellent card, I've seen him used several times vs me in a white weenies deck and would certainly consider him. 2. Banisher Priest : Not too comfortable with more 2 white mana for a 3 drop, not a bad card though.3. Cartel Aristocrat : What situations would I actually want to save him? Seems sometimes counter-intuitive with this deck. Maybe you could enlighten me on this some more?
4. Fiendslayer Paladin : Love this card, but because this is budget I could not add him. Obzedat, Ghost Council was my choice for expensive card because he is more in the mana range I wanted to cover (have plenty of 3 drops, needed higher drops)5. Mogis's Marauder : Too aggressive, this deck doesn't really need aggression imo. I have sideboarded him in a couple of times.Thanks for the input!

@BobTheImam:No problem. About the Cartel Aristocrat , for some reason I originally thought that the protection would stop trample from getting through. But, I looked it up, and that is not the case. You can ignore that suggestion. If you aren't going for aggression, then maybe add some Orzhov Guildgate to help you with any color problems you might have? Anyway, nice deck!

Did you think about putting Gift of Immortality in? I think it would be great since it can help make Zombies and combos with High Priest of Penance .

Dark Betrayal, Orzhov Keyrune, and/or Vizkopa Confessor?

If I were to add any of those cards it would be sideboard options. Not much to remove atm. I will try playing the Gift of Immortality in place of Ordeal of Heliod and give it a shot.