The strategy of the deck is to let the opponent slowly bleed out. Of course the life points gained through extort help alot to survive and can be used extensively as a resource.
To generate card advantage I use 4 copys of Phyrexian Arena, one life for one card is already good under nomal circumstances but herethe lifeloss is really miniscule.
No Mercy lets the opponent hesistate to attack me instead of other opponents. Again, with such a large supply of life points you can take a few more hits than with a regular deck. I play this card only twice, because additional copies have no further effect.
Attrition is used to rid yourself from dangerous creatures, and this repeatedly because of the next card:
Phyrexian Reclamation brings back destroyed or sacrificed creatures and generates card advanted while doing so, 2 life and mana is a low price to pay in such a deck.
The Extorts: The heart of the deck, with this, the enemy is slowly worn down and my life points are replenished. Thrull Parasite, Syndic of Tithes and the Basilica Guards are mainly in the deck because they have the ability to extort at a good mana / performance ratio. The first ability of Thrull Parasite is negligible, but can be useful depending on the opponents deck, as it can finish off a planeswalker at one remaining loyalty counter.
All these extort triggers devour a lot of mana, especially when there are a lot of them in play, this is why I added four Crypt Ghast.
The Pontiff of Blight gives all my creatures the extort ability a second time and is therefor considered to be a finisher. Because you don't want to see him in your starting seven he is included only twice.
The Treasury Thrull brings extort to the table aswell as a passable large body, it also has the advantage of bringing back destroyed enchantments and creatures to your hand, thus synergizes well with the Necrotic Sliver, which kills permanents of any kind. Of course the sliver can be recycle with Phyrexian Reclamation and is therefore played instead of Vindicate.
At first glance the Whitemane Lion seems a little out of place in this deck, but the fact that he can be bounced to his own trigger makes him excellent as a repeated extort enabler. You can play him at the end of your opponent's turn, bounce him and extort the opponents for your remaining mana. In an emergency, he is also a spontaneous blocker or can protect your other creatures from removal.
The land base consists of 24 lands, so you can reliable play a land for the first turns. By combining Cabal Coffers and Urborg, Tomb of Yawgmoth you can generate a significant amount of mana, while Crypt Ghast also gets better with Urborg, Tomb of Yawgmoth in play. This is the reason I play 4 Godless Shrine instead of eg Isolated Chapel. There is only a single Scrubland because I have only a single one. The Marsh Flats are there to fix the colors.
In a few cards I'm still unsure whether and how to include them, these include three ways to add a form of discard to the deck, twice in the form of creatures that I can bring back, the Thrull Surgeon and the Corpse Traders. More mana efficient would be Castigate but this can't be reused.
Another consideration would be Dark Ritual, I am aware that you should only play this card in combo decks, but here a topdecked Dark Ritual can still be used as a extort enabler.
Divinity of Pride is a great finisher and should be a 8/8 flyer for 5 almost all the time but I don't know if he is really needed. The same is true for the Rhox Faithmender who increase my lifegain even further.
If you have ideas on how to improve the deck, bring it on.
PS: If you suggest a card to add please also state what you would cut to include it. The deck is full as it is and adding cards is not a problem, but what to cut for it.
