It's been Nahiri, the Harbinger that has stolen the fair-deck players' hearts in Modern recently, reigniting the dormant Jeskai deck and thus making it the most-likely home for Ancestral Vision (albeit mostly as a sideboard card). But Nahiri isn't the only Shadows over Innistrad card that has made its way into Modern. Kalitas, Traitor of Ghet has found a home as the four-drop of choice in Jund, a slot which has been occupied over the past few years by a variety of cards from Chandra, Pyromaster to Huntmaster of the Fells to Pia and Kiran Nalaar.
Kalitas's four toughness makes it an idea threat on four mana since it dodges both Lightning Bolt and Abrupt Decay, and in any of Modern's removal-heavy midrange decks you can make a pile of Zombies in a hurry. No brains are safe from the hordes of decomposing flesh Kalitas will send your opponent's way. It's become increasingly important in recent years to be able to close games quickly because your opponent will eventually topdeck their way back into the game, and Kalitas does that better than any threat in recent memory – to the point where a deck like this would not be viable without it.
Because Kalitas allows you to cut a color, you are rewarded with a more consistent and less painful manabase plus the ability to play seven utility lands between Creeping Tar Pit and Tectonic Edge. There are still enough fetchlands to support the Delve cards in the deck, and Hallowed Fountain allows your Engineered Explosives to still be cast with a third color of mana.
The rest of the list is a typical array of powerful interactive spells. One surprise may be the relatively low number of discard spells here when compared to similar decks like Grixis Control and Jund, but trimming them makes sense in the presence of Ancestral Vision. Vision promotes playing for a longer game and those discard spells eventually become dead draws, negating some of the card advantage you are building your deck around. The Vendilion Cliques in the list give the deck some more hand disruption while also helping you turn the corner and they play nicely with your heavy counterspell package, making it easier for you hold up mana usefully on your opponent's turn.
The splits on the counters make a lot of sense. Mana Leak is favored over Remand since the deck doesn't take much advantage of Remand's tempo and would rather just trade resources and leverage its Visions. Three Cryptic Commands is heavy; outside of Kalitas you rarely have to tap mana on your turn, so holding it up is fairly easy and you'd be surprised how fast your various Zombie tokens and Snapcaster Mages can finish your opponent even if they stabilize the battlefield with bigger creatures. Still, it's important to realize that these counterspell splits should be constantly shifting with the metagame, there will never be a universally optimal configuration.
Like the counterspell package the removal suite is highly customizable, and with the card velocity Ancestral Vision grants us diversifying is the best strategy. Note that despite costing three mana, Nahiri makes Hero's Downfall an important singleton in this package. Dreadbore has become a common singleton in Jund lists for the same reason, and Downfall may be better in this shell anyway since Snapcaster Mage amplifies the advantage of instants over sorceries. The one minor change I would make is swapping the Ultimate Price for a Go for the Throat, since they both miss most artifact creatures (with Vault Skirge and Master of Etherium being notable exceptions) but Go for the Throat kills Thought-Knot Seer and Reality Smasher.
I tend to highlight some of the wackier decks available in Modern in this space, but you can innovate while staying firmly inside the box. All of the cards in this deck are good Modern cards, but when pieced together in a unique way we have something that can take players by surprise while still guaranteeing you that you won't be completely outclassed on card quality if things don't go exactly according to plan.