The Commander
Teysa, Orzhov Scion: The master herself. The reasons she leads our deck are manifold. She acts as a "limitless" form of instant creature removal, a strong form of board protection, a pretty potent rattlesnake, and a powerful trigger-doubler. She provides a lot for the deck, and even works as a piece of many combos.
The Supporting Cast
Blood Artist: Death triggers are the best, and this being a drain effect means that this is basically a manifestation of this deck.
Nether Traitor: This card provides for many infinite loops, and even without that, it is an easy and powerful engine for token generation and triggered abilities.
Soul's Attendant: Creatures come in, they give you life. Basic idea of the deck.
Suture Priest: Fun card to play against opposing token decks, and also fuels our life gain strategy.
Rhox Faithmender: Decent butt, white creature just in case, lifelink is a small bonus too, and doubling our life gain can be very powerful, especially if we have a drain effect like Sanguine Bond.
Viscera Seer: 1 mana, black creature, effective sacrifice-outlet. A+
Zulaport Cutthroat: Not quite Blood Artist, but it does have it's moments. It's still an extremely powerful effect here, and we want/need it.
Soul Warden: Another soul sister.
Deathgreeter: The black (and better) soul sister.
Pitiless Plunderer: This card turns all sac-outlets into Phyrexian Altar+. Very, very powerful. Also, it's a black creature for gravy.
Ophiomancer: Incredible token engine as it provides a stream of black creatures, one every upkeep. Just needs any sac-outlet and it'll provide an army of Spirits.
Gray Merchant of Asphodel: Potentially HUGE life gain and drain on a black body. Awesome.
Vizkopa Guildmage: Provides a large drain effect on a multicoloroed body, and can often end games out of nowhere. Even the lifelink can be useful. Good stuff all around.
Mentor of the Meek: It doesn't take a lot to make this an amazing card draw engine, and it can even be applied to some loops to draw your whole deck.
Skirge Familiar: This deck has the potential to draw cards by the gobs, so discard outlets are good to have around. Can also be applied to some loops to make infinite mana or draw your whole deck... or both.
Smothering Abomination: Draw every time I sacrifice a creature? Yes, please! This card ranges from a steady stream of cards, at least one every upkeep, or it can deck you. Crazy strong. It is worth mentioning that it is not a black creature unfortunately.
Ashen Rider: Basically just a staple removal card in Orzhov. The fact that it can be recurred makes it very worth the inclusion.
Requiem Angel: Basically, it's a second copy of Teysa on a better body.
Kokusho, the Evening Star: Similar to Gray Merchant of Asphodel, but it's a death trigger on a 5/5 flyer.
Grave Titan: Black army in a can. Too good not to play.
Solemn Simulacrum: This card gets flak every now and then for being not as good as people think it is, but I am a big supporter of this card. It is just plain never bad, and that is good enough.
Martyr's Cause: Just another sac-outlet. It's effect has it's moments as well.
Carnival of Souls: Dangerous at times, but if you have at least one ETB life gain trigger, it can make massive amounts of mana. Also, what other deck can play this card?
Moonlit Wake: Death trigger life gain on a noncreature permanent makes it more resilient. Not to be underestimated.
Fanatical Devotion: Same as Martyr's Cause. This deck needs a critical mass of sacrifice effects because of how important they are to how the deck functions.
Boon Reflection: The worst of the life doublers, but I like playing all of them. It's a worthwhile effect even at 5 cmc.
Zombie Infestation: Powerful effect that can power some loops.
Dark Prophecy: This card can be dangerous, but the risk is always well worth it. Once landed, it will draw you cards in big grips. And again, what other deck can play this card to such effect? But seriously, it can be dangerous. If you want to perform a loop with this on the battlefield, you could end up decking yourself before you kill the opposition. Make sure to remove it yourself somehow if it'll cause issues.
Gift of Immortality: This card is underestimated to an insane degree, but in this deck, it is ridiculous. Stick it on any creature, sacrifice it every turn for an army of Spirits. That is the worst case scenario of the card. If you can land in on anything with an ETB or death trigger, it can be devastating for your opponents.
Greed: This is another underrated card. Just one B and 2 life for a card is a steal.
Dictate of Erebos: Do I need to explain why this is good? Nah, I don't think so.
Bitterblossom: Comes down early and provides a steady stream of black tokens.
Anointed Procession: Doubling tokens means doubling other triggers as well, and when you combine this effect with Teysa, it often quadruples your effects. Very strong.
Phyrexian Arena: I have seen some hate about this card recently, but I am an avid supporter and defender of this card. Playing this early is an incredible boon, and we'll worth the "bad" late game top decking, especially in Orzhov.
Black Market: This is a fun card that I just like to include because it has a high ceiling that if you can pull it off, is a blast to abuse.
Phyrexian Reclamation: This card is very strong. It has such a small opportunity cost for such a great, repeatable effect.
Sanguine Bond: The best version of the life gain to drain effects.
Phyrexian Altar: Arguably the best (if not, then the second best) sacrifice outlet. Colored mana for tokens is great.
Codex Shredder: This card can pull any card from your graveyard, and that is a good effect. It's also a permanent, so it can be recovered somewhat easily. Also, it slowly stocks up your graveyard for ya.
Gilded Lotus: 3 repeatable colored mana, for 2 mana opportunity cost basically. Very good.
Vedalken Orrery: I have been running this card in every one of my decks for years as being able to cast everything at the best possible moment.
Alhammarret's Archive: Let's be honest, I probably would have been playing this card if it only did one of the things it does. It doing both just makes this kind of crazy here. Perfect for us.
Panharmonicon: Another trigger doubler, and well worth it here.
Aetherflux Reservoir: This is just fun, it's not a storm win-con or anything, but it gives us some incidental life gain, and can cause some pretty fun scenarios where you can hold the table hostage.
Mind's Eye: This is a one card draw engine. 1c per card is very good. Strong in most decks, and probably underrated.
Mirage Mirror: Oh, the things that can be done with this card. It can be literally anything, and that means a lot. Normally it will act as a second doubler of some kind.
Thran Dynamo: Similar to Gilded Lotus. 3 repeatable colorless mana for the small opportunity cost of 1 mana.
Trading Post: This card does a lot of good things, but most often, making a white Goat for 1c and 1 life is pretty decent.
Well of Lost Dreams: Easy to trigger, and allows us to draw many, many cards.
Skullclamp: Broken? Yeah, broken.
Ashnod's Altar: Next in line to Phyrexian Altar for best sac-outlet. 2 mana per creature is great.
Sol Ring: Duh.
Mana Crypt: Extra, extra good in this deck since life usually means nothing to us.
Anguished Unmaking: Sometimes, people play cards we don't like. This takes care of those things.
Utter End: ^Ditto.
Minions' Murmurs: Lots of creatures = lots of cards. Don't sleep on this card.
Plague of Vermin: With at least one soul sister-type effect, this becomes dumb. It will win the game 99% of the time.
card:Debt to the Debtless: Big X Spells win games they say, so here it is.
Ancient Craving: Decent draw spell-it's necessary.
Army of the Damned: Lots of black Zombies means lots of dead opponents. Flashback is gravy.
Living Death: Either a board wipe or a mass reanimate. But why choose? This is both! Good stuff.
Ambition's Cost: Literally the same as Ancient Craving.
Overwhelming Forces: Wipe out one players stuff, and draw oodles o' cards.