Obzedat, Ghost Council carries the torch as the new general for the previous commander Ghost Council of Orzhova in what has slowly evolved into my Drain Life themed deck. The basic premise is to drain opponents of life points at every opportunity while incrementally gaining card advantage and destroying key permanents. The deck is slow and grindy, but it definitely stays true to its theme and promotes a controlled game state without drawing too much attention or hate.
There really isn't a lot to the deck, but the cards do break down into several distinct categories.
The deck runs 9 of the 13 possible Extort cards that were printed in Gatecrash and Dragon's Maze. If there was enough room I'd run them all, but some of them are just not powerful enough on their own to warrant inclusion or are just plain too expensive. The beauty of the Extort mechanic is that it drains each opponent for each activation, so not only are you efficiently damaging your opponents you are also gaining lots of life in the process. Some of the Extort creatures are small and you may be tempted to cut them, but they will go a long way towards dealing lots of early damage and providing the deck plenty of early plays. The deck also runs a lot of recursion engines so that you never run out of spells to play with which to trigger Extort.
Life Drain Spells:
Although the deck does not play the iconic Drain Life, it does run 4 of the best Life Drain sorceries that you can run. Exsanguinate and Debt to the Deathless are particularly powerful in that they drain all opponents.
Bleed Life Effects:
One of the keys to the deck is to find cards that can repeatedly damage your opponent with little or no additional mana cost since you want your mana available to pay for Extort or to further advance your board. There are several cards available that will slowly bleed away your opponent's life total for doing things that they would normally want to do. Put a creature into play? Suture Priest and Blood Seeker say hello. Put a land into play? Polluted Bonds drains you for two? Draw a card? Underworld Dreams hits you for one.
Cards I have considered Blood Clock/Umbilicus: These cards fit right into the theme, either draining the opponent life or setting their board back a permanent. The problem is that the 'enters the battlefied' effects of creatures has gotten so good that I would often help the opponent rather than hurt them and they rarely drained the opponent like I wanted. Stab Wound, One Thousand Lashes, Pillory of the Sleepless: Great cards that do double duty in the deck, but I hated being torn between wanting these cards on the battlefield and wanted to Wrath the board. I have replaced them with cheaper removal. Blood Artist, Falkenrath Noble: These cards need more support in the form sac outlets to be effective.
+1 Scholar of Athreos: A card that can repeatedly drain the opponent giving me a nice outlet for all the black mana the deck can produce. It's also much cheaper than the alternatives allowing me to trigger Extort more often.
+1 Underworld Coinsmith: Another card that can repeatedly drain the opponent, with a nice little life gain upside when I trigger constellation. It's also another cheap Extort enabler.
+1 Ob Nixilis, Unshackled: Card is so good at punishing tutoring that it slides into the deck perfectly.
-1 Agent of Masks: Fine card that just ended up being too slow.
-1 Day of Judgment: The didn't need all 3 Wraths so I cut the one that doesn't have the "cannot regenerate" clause.
-1 Conjurer's Closet: The deck wants 2.5 of these cards, so for now I'm keeping Erratic Portal and Cloudstone Curio and cutting this.
Apparently, I wasn't over 99 cards before so the decklist only showed 98 in the MD...
+1 Bontu's Monument - 1 mana cost savings on all my black creatures (22 plus Obzedat) plus life drain to each opponent for each creature I cast makes this a nice add to the deck.
Fate Reforged Palace Siege - I wavered on this one. At one time or another, it has replaced Oversold Cemetery and Debtor's Knell as a recursion piece that can also be a continuous life drain effect if I need it to be.
Dragons of Tarkir
Magic Origins Alhammarret's Archive - I tried to resist putting this into all my decks, but it was tried out here as a suggestion from another MTGS user. The lifegain boost is very useful in this deck, but I was very surprised as to how often the card draw part was relevant. Shadows of the Past - I took this for a whirl, but the ability is just too expensive.
Shadows Over Innistrad Anguished Unmaking - The life loss is inconsequential for the added flexibility this has over some options, but not so much as to want to play this over something like Mortify or Vindicate but rather in addition to them if he deck has space. Sorin, Grim Nemesis - The abilities are on theme, the +1 ability affects all opponents, and doubles as removal.
Conspiracy: Take the Crown Kaya, Ghost Assassin - When I had more ETB life-drain in the deck, this was pretty good. I've since reduced that theme down a lot and this card was cut because of it. It's fine, but not great unless you have a ton of stuff you want to bounce.
Kaladesh Aetherflux Reservoir - I didn't really want to run stuff that only gained life, but there are a few exceptions to this. I cannot decide exactly where this will fit in my long term plans for this deck. Kambal, Consul of Allocation - Fits right into what this deck wants to do. Panharmonicon - Amazing card in this deck; all the ETB life drain triggers and stuff like Suture Priest all get doubled up. I pulled a bunch of these kinds of cards when I reconfigured the deck and this went with it, but it is possible to run this and be very happy about it.
Hour of Devastation Crested Sunmare - I have 28 cards that can gain me life in some fashion along with 4 other cards that trigger when I gain life. They are all pretty awesome in this deck, so I expected nothing less from Crested Sunmare. I was not disappointed with it here. Torment of Hailfire - I'm usually not a fan of cards that give the opponent a choice, but I can generate some mana at time that can make this a pretty efficient finisher. I liked that it hits all opponents and not just one like Blood Tribute.
Commander 2017 Alms Collector - This is a fine card that ended up in another deck.
Ixalan Dire Fleet Ravager - I had high hopes for this but it was underwhelming at best whenever it got played. Raiders' Wake - Excellent card that rarely triggers unless I get Raid-ing so I ended up pulling it. Vona, Butcher of Magan - This is a strong addition to this deck; it's removal, some lifegain, and a reasonable beater.
Rivals of Ixalan Elenda, the Dusk Rose - This just isn't good enough; maybe if I were more Vampire-tribal oriented then this might be worth it for the token generation. Profane Procession - This is expensive, but it exiles the offending creatures and there is obviously some upside when it flips into Tomb of the Dusk Rose. In the end I felt like I just had enough better options. Twilight Prophet - This card is pretty amazing if it sticks around, generating card advantage, draining life, and essentially doing everything I could ask for of a 4-drop.
Dominaria Arvad the Cursed - The thematic tie-in would be that it as Lifelink, but the +2/+2 bonus would apply to 7 other creatures plus my Commander. Given enough Legendary creatures, this is potentially worthwhile, but for the meantime I'll just keep it in the back of my mind that this is an option. Chainer's Torment - The first two chapters drain life from everyone, but the last chapter gives us what should be a huge token. I'm skeptical that this is going to work out well given that the token is vulnerable and has no evasion, so I'm going to pass for now. Demonlord Belzenlok - The card is kinda ridiculous, but I think I'm going to pass on adding it here. There is at least one other deck where this has found a home and I'm trying to spread out my "staples" among my decks rather than putting them in every deck. Lich's Mastery - I think that this might be the exact place that a card like this makes sense. At first I was really leery of this card, especially given that I don't actually produces a lot of permanents to make sure that I don't die to my own Lich. But the fact that it has Hexproof and that I can exile cards from hand or the graveyard makes me think that the chance of that happening are very slim. I'm going to give it a whirl here.
Battlebond Archfiend of Despair - This is really expensive at 8 mana, but it is perfect for what this deck wants to do thematically. The plan is to remove another late-game card in Torment of Hailfire to fit this in. Regna, the Redeemer - With plenty of ways to trigger Lifegain, this seems like a solid potential addition to the deck. Virtus the Veiled - Seems pretty saucy if I can give it evasion or clear the way for it.