Abyssal Gatekeeper - Easy creature trades/Removal
Altar of the Brood - Milling (to power up Guiltfeeder)
Apprentice Necromancer - Grave Recursion (Get back creatures who died before Shirei came into play)
Attrition - Spot Removal
Bile Urchin - Damage Dealer
Chimney Imp - Hand Control
Contamination - Mana Control
Death Cultist - Damage Dealer
Diabolic Intent - Tutor
Exsanguinate - Finisher (Alt-Win condition)
Fume Spitter - Field Control/Creature Removal
Guiltfeeder - Finisher
Infernal Tribute - Card Draw/Card Advantage
Lightning Greaves - Hexproof for Shirei or Guiltfeeder
Pilgrim's Eye - Ramp
Shirei, Shizo's Caretaker - Key combo card, need to get out ASAP
Smokestack - Field Control/Finisher
Thoughtpicker Witch - Deck/Draw Control
Strategy:
This deck revolves around the central card Shirei, Shizo's Caretaker and a number of cheap 1 power creatures with special abilities that allow them to sacrifice themselves. This is important because there will be times when you have no sac outlet on the field or you do not have enough free mana to use it and you will stall out. With creatures who can sac themselves, you can use their effects every turn, since they come back even on opponent's turns.
Our opponent isn't just going to let us do this, however. That's why the deck is loaded with a bunch of different control spells and enchantments that will allow us to drag out the pace of the game and ping the enemy to death with infinitely recurring creatures.
Use Thoughtpicker Witch, Chimney Imp, and Contamination to prevent your opponent from drawing into answers. Your biggest priority should be to use the witch to dump any mass removal to the graveyard since Lightning Greaves cannot protect Shirei if the spell has no target. Following that, dump any counterspells. Then, focus on big bombs or artifact/enchantment removal that may disrupt your lock.
Smokestack is particularly devastating in this deck. Even with only one or two counters on it, you can easily surge past your opponent when they dip down to saccing lands when they run out of other permanents to lose.
You should be able to win just from damage through Death Cultist and Bile Urchin, but if things get hairy, you have a few alternate ways to win. Dumping a ton of mana from Cabal Coffers into Exsanguinate is an easy, albeit anticlimactic way to win. If that fails, Guiltfeeder can be a heavy hitter with a few cards in the opponent's grave, and with all the removal options at your disposal with Attrition, Abyssal Gatekeeper, Fume Spitter, and Smokestack, it should be easy to focus down the weakest player first, remove their blockers, and hit them hard for a lot of damage. He also comes back into play if killed while Shirei is on the board, due to having 0 power, so he is immune to most combat tricks short of instant speed exile. Lastly, Altar of the Brood can earn you a reliable win via deckout if you play it early enough. If you're good enough, you can combo that with Thoughtpicker Witch to take care of multiple good cards coming up, or Chimney Imp to kill spells they are holding due to a Contamination on the board that prevents them from casting it.
