A good idea, and I like that extort significantly lessens the difficulty of flipping the Chalice of Life  ^Flip . Though part of what makes extort function so well is focusing the deck on lower cost spells, so you have the extra mana to extort. And while Stuffy Doll is useful, and Exquisite Blood gives it a similar effect to lifelink, I don't think it fits in with everything else quite as well. You should consider sideboarding them for either the other 2x Pacifism (cheap removal) or the other 2x Elixir of Immortality (cheap lifegain/graveyard return). I also feel that Treasury Thrull , while very useful, is a bit too expensive. Consider adding in more Gravepurge if you really like the effect.

Again, by dropping your overall mana curve, you will have more leftover mana to extort every spell you cast, likely multiple times. And trust me when I say that every trigger of extort is a nail in their coffin.

What if I increase the quantity of Orzhov Keyrune and/or Traveler's Amulet ?
Is there a way I can bring Exquisite Blood out earlier? e.g. something that pulls it from my library.

Not in standard that I'm aware of. Though Diabolic Revelation and Increasing Ambition are good for searching for whatever you want, they don't put it into play. Perhaps run 2x Exquisite Blood and 2x Increasing Ambition ? Maximize your chance of pulling the Exquisite Blood , and since they are the exact same cost if you cast Increasing Ambition to fetch Exquisite Blood you know you can cast it next turn. That way your top end is only CMC 5, and you'll only have 4 cards out of 40 (nonland) that mana-expensive. And if you have the Exquisite Blood already out on the field, then the Increasing Ambition can search for anything else you might need. Just a thought.

I suggest you edit as per the following:

2 Knight of Obligation 2 Basilica Guards

1 Plains and Swamp for 2 Transguild Promenade

Gravepurge and 2 Traveler's Amulet for 3 Oblivion Ring

2 Stuffy Doll for 2 Pacifism

2x Elixir of Immortality and 2 Chalice of Life  ^Flip for 4 Orzhov Charm

and if you can acquire the maybeboard cards, that would help alot in your deck.

Here are a few suggestions, pick and choose what you like! By my comments I have no intention of being negative. I'm just sharing my two cents.

1. You're 3-drop slot can be filled with a more efficient card than Basilica Guards . Cut.
2. Stuffy Doll doesn't really fit; you don't have a way to deal massive damage to it. Cut.
3. Treasury Thrull might be too mana-intensive without the Ghast out, so I'd drop him as well.
4. Traveler's Amulet isn't necessary in a two color deck. Cut.
5. I think Knight of Obligation s slot can be filled more efficiently too. Drop to a 2-of.
6. Not a fan of Elixir of Immortality or Orzhov Keyrune . Maybe SB card for the Elixer?
7. Gravepurge isn't necessary either

With the above cuts, you're left with 14 slots. I recommend adding 4x Vampire Nighthawk , 2 lands that fit the curve, 3x Orzhov Charm , 3x Kingpin's Pet , and 2x Rhox Faithmender .

Hmm that might be too many creatures. Oblivion Ring , as MTG_Player mentioned, would be a good choice as well.

Again, my two cents. Not perfect advice, but hopefully I've suggested at least one thing you like!

@ ducttapedeckbox and MTG_Player

You guys make great points for an all out extort deck but my idea was to revolve around Chalice of Life  ^Flip while using extort to flip it sooner. Elixir of Immortality was more because for 3 mana I can get 5 life.

Any ideas on how to better achieve this?

I plan to make a 3 colour extort/cipher deck later but I need to finish this one first. For now i agree with most of your points about reducing and cutting cards so I'll put that in an update

after looking at this update I could probably reduce the amount of creatures