Remember when Return to Ravnica Block was legal? What was the most dominant deck of that format? The decks that come to mind are the Devotion decks, and perhaps the best of the bunch was Monoblack Devotion. With Magic Origins black has gained some very powerful tools that are worth looking into. At the same time many of the tools that were staples of the Monoblack Devotion archetype have now disappeared. Personally I think that the archetype can be resurrected though it may look slightly different than previous versions.
Looking back here are some of the staples from the previous versions of Monoblack Devotion:
Nightveil Specter / Lifebane Zombie
Gray Merchant of Asphodel
Various Removal Spells
First of all the removal spells are replaceable and many of them are still around in the current Standard format. Beyond the removal spells all that is the same is Thoughtseize and Gray Merchant of Asphodel. I would argue that these are two of the most important cards of the bunch, though there are still many cards being given up. Thoughtseize is the best conceivable one mana play for this type of deck, and this deck doesn't want to play a creature on turn one as it's not an aggro deck. This is the best Thoughtseize deck because of how easy it is to cast on turn one, with all the untapped black sources. Without Gray Merchant of Asphodel the deck couldn't be called Monoblack Devotion as there wouldn't be enough of an incentive for black mana symbols. Let's go ahead and see what replacements are available once Magic Origins becomes legal for the other pieces of Monoblack Devotion.
Pack Rat: In order to play a Monoblack Devotion deck you really do want to be playing a two-drop. There is not a two-drop that compares to the power level of Pack Rat, but we can still make do. Personally I believe the best black two-drop in Standard is Pain Seer. If you can supplement Pain Seer with lifegain it can be a reoccurring source of card advantage. The other option is to look to play another color in search of two-drops, though this does change the deck substantially. If there was a two-drop with double black in the casting cost it would almost certainly go in the deck, but Wizards was correct not to print one.
Mutavault: After talking about Pack Rat it is important to mention Mutavault. Part of the reason why Pack Rat was so good was because it was played alongside Mutavault, which could essentially add an additional rat to the count. Mutavault was also one of the best lands to have in a monocolored deck as it was essentially a free addition. Since Mutavault is no longer available I would expect to see Nykthos, Shrine to Nyx take its place, or we will be seeing a splash in devotion strategies.
Underworld Connections: This was the way of creating a continuous stream of card advantage, that couldn't be bothered by a Wrath effect. Having noncreature permanents is super important, and this was one that also helped your devotion count. When playing a midrange style deck you do want some sort of card advantage, but looking at Magic Origins, let's check out Demonic Pact. This might actually be better than Underworld Connections if you could easily destroy it before the fourth mode comes into play. Losing to your own card is a terrible feeling. With that said the three other modes are all very strong and it is like having three cards in one, while also enabling Devotion.
Nightveil Specter / Lifebane Zombie: This might be the toughest part of the previous Monoblack Devotion deck to attempt to replace. Magic Origins has brought some strong four mana plays, but we really do need things to do on the third turn; more specifically we need creatures to play. The most powerful three mana black creature that is available for this deck before the release of Magic Origins is likely going to be Herald of Torment. With Gray Merchant of Asphodel and potentially Demonic Pact there should be enough lifegain to off-set the life being lost. There are other options though. Master of the Feast does hit hard though I'm not sure it is worth it because of the card advantage given away. Perhaps something like Master of the Feast or Mogis's Marauder would be good if this was an aggro deck.
Once we take Magic Origins into account though, we should consider Liliana, Heretical Healer. The issue is that we may not be playing that many other creatures, so flipping her won't be easy. On the other hand the lifegain is very relevant as we will be losing life in various ways, and she provides two black mana symbols towards devotion. This is one I'm unsure on but likely has the highest upside of the bunch. Another three-drop that actually could work here, and double as a two-drop is Silumgar Assassin, though this is a card that hasn't really seen any Constructed play up to this point.
Desecration Demon: This has to be the easiest card to replace of the bunch. Desecration Demon was good but could be thwarted by small creatures getting sacrificed to tap it down. Erebos's Titan may be an upgrade to Desecration Demon, as a lot of the time your opponent won't have creatures in play because of all your removal spells. An indestructible 5/5 is a pretty big game, not to mention you can bring him back from the graveyard given the right circumstances. However, the best part of Erebos's Titan for Monoblack Devotion is his three black mana symbols. I expect to start see players going Erebos's Titan into Gray Merchant of Asphodel.
Alright now it's time to come up with a tentative new list. This is my initial stab at coming up with a competitive list, though it is by no means a finished product:
As you can see this list is trying some things out, and is opting not to try out other things. Not all the options can be explored in one list, and certain cards need a lot of work in order to make them very good. Starting with the spells Thoughtseize is an obvious four-of, and there are also a couple of Sign in Bloods. Previous versions of Monoblack Devotion sometimes played a couple of Sign in Bloods, and I especially like it in this list as a form of card advantage. There are not more copies because it doesn't help devotion similar to cards like Underworld Connections did. I do think it's better than Read the Bones in this deck because of it being one less mana, and you should have access to double black on turn two pretty much every time.
The removal spells are very reminiscent of the old versions of Monoblack Devotion. It has already been proven that Bile Blight, Ultimate Price, and Hero's Downfall are the best black removal spells in Standard, so it seems correct to run a mix of those. Bile Blight is especially good in this type of deck because the mana requirements are easy, and it is the best way to answer tokens, which are otherwise quite annoying. The mass removal spells are delegated to the sideboard as they are much more matchup specific. Hero's Downfall remains the most efficient way to answer a planeswalker, and with the recent printing of more planeswalkers it seemed correct to just add the full four copies of the card.
Moving onto the creature base, Pain Seer seems like it has a lot of potential to produce card advantage when played alongside other removal spells. However the fact that you can flip a five-drop or even the single seven-drop may make Pain Seer a lot worse. Pain Seer may only work in a Monoblack Aggro deck, but I do think it is worth trying out here. Silumgar Assassin is another pseudo two-drop; this whole morph cycle has been quite impressive, and Silumgar Assassin has what it takes to be playable in Standard. A lot of the times he will be unblockable, and sometimes a 2/1 unblockable is good enough, disregarding his ability to morph.
For the three-drop slot there is a mix of both Herald of Torment and Liliana, Heretical Healer. First of all you don't want to be playing four copies of Liliana, Heretical Healer as she is legendary. These two cards actually work quite well together, as Liliana, Heretical Healer is a great target for bestow because of her lifelink, and Herald of Torment provides evasion. When Lifebane Zombie and Nightveil Specter were in Standard together you would often see a split like this.
The other creatures that aren't obvious includes are the single Erebos, God of the Dead and the Abhorrent Overlord. I opted not to include Demonic Pact since there aren't actually any ways you have to destroy it. This makes playing it very scary, though it still could be correct to include. However, I would feel safer if I was splashing for something like Utter End that could deal with it in a pinch. Erebos, God of the Dead is a replacement source of card advantage, and many previous Monoblack Devotion decks also included a single Erebos, God of the Dead. Both Abhorrent Overlord and Erebos, God of the Dead are good ways of using excess mana created from a Nykthos, Shrine to Nyx. While Nykthos, Shrine to Nyx isn't super important in the deck, having big mana plays later in the game is sweet and is the reason why Abhorrent Overlord is in the deck, though it still might be bad.
The rest of the list should look fairly similar to a typical Monoblack Devotion deck. There are some scry lands to help filter your draws, and the sideboard has key components against just about every matchup. Having access to Duress is huge as discard is great against any slow deck, and allows you to just have essentially more Thoughtseizes in the deck after boarding. There are more Drown in Sorrows than Languish because Languish kills more of your own creatures. Drown in Sorrow is still better against the very small creature decks, which may be this deck's biggest worry. Similar to Abhorrent Overlord the Soul of Innistrad is another late game mana sink that works well with Nykthos, Shrine to Nyx, and is best suited in the midrange and control matchups. It is important to remember that Monoblack Devotion was not just very good because of the maindeck, the sideboard is what allowed it to gain an edge versus many matchups. Many of the best sideboard cards right now are black, which is another reason this deck seems like it is set up to make a comeback.
Thanks for reading,