I've seen Black Devotion decks in Modern before. With cards like Phyrexian Obliterator and Geralf's Messenger, there are certainly powerful enablers for the archetype, but the issue has always been how the lower end pieces don't fit into what the rest of the deck is doing. Typically these decks use a bunch of sticky threats like Bloodghast and Gravecrawler, taking advantage of some Zombie tribal synergies, but those threats want to be aggressive, and Phyrexian Obliterator doesn't really fit with them.
So what I like about this deck is that it abandons the devotion plan, instead going full-on aggro with the addition of Gifted Aetherborn. You still have the tribal synergies and a touch of devotion with the singleton Gray Merchant of Asphodel and some Phyrexian Obliterators in the sideboard when the games slow down, but this is an aggro deck. Rather than Nykthos, Shrine to Nyx in the utility land spot, we see Mutavault, another sign of commitment to attacking.
With Death's Shadow running rampant over Modern, spot removal has taken precedence over sweepers like Anger of the Gods, meaning cards like Gravecrawler, Bloodghast, and Geralf's Messenger are at their best, and you even have access to the best disruption with Thoughtseize and Fatal Push, so limiting yourself to one color doesn't come with a huge sacrifice in power level.
Even better, it looks like Amonkhet is bringing some new toys for this deck to play with, most notably Dread Wanderer and Plague Belcher. The former is another aggressively costed one-drop that is likely better than Cryptbreaker, although you could want more than eight one-drops, while the latter functions with a limited drawback since you can so easily recur whatever creature you target with its ability. Even better, target a Geralf's Messenger and trigger undying, effectively adding six power to your battlefield for three mana.
Graveyard hate is going to be an issue, especially something like Rest in Peace that permanently punishes your creatures for being undersized, but with an increase in the fetch land count you can easily splash a card like Abrupt Decay. There are a lot of options here, which is surprising for a deck that is limited to one-fifth of the color pie. Lots of Modern decks try to take advantage of the easy mana fixing that fetch lands and other nonbasics provide, so it's nice to see someone taking a more honest route, even if they're still utilizing fetchlands.
- 4 Bloodghast
- 3 Cryptbreaker
- 3 Geralf's Messenger
- 4 Gifted Aetherborn
- 4 Gravecrawler
- 1 Gray Merchant of Asphodel
- 4 Relentless Dead
- 1 Kalitas, Traitor of Ghet