Ancestral Vision is unbanned in Modern, and it will revolutionize blue decks. Blue has always thrived on card advantage, and Ancestral Vision is now the most powerful and efficient card-drawing spell in Modern. Treasure Cruise crashed through Modern like a tidal wave, and Ancestral Vision offers much of the same potential.
Ancestral Vision is slow in the sense that gratification is postponed, but in terms of mana it's incredibly cheap and therefore efficient. The true cost of drawing cards is the opportunity cost of the mana spent. Ancestral Vision allows blue decks to amass cards without significant mana expenditure, so mana can be spent elsewhere. Formats like Modern are fast and brutal, and there isn't time or mana to spend on cards that don't have an immediate and tangible impact on the game. Ancestral Vision provides cards without the need to hit the brakes, and that's what sets it apart from the rest.
You might think Ancestral Vision was banned because it was part of a busted deck in the early days of the format, but it has actually been banned since day one, preemptively banned at the format's inception. Quoted from the article officially introducing the format to the world:
The combination of Ancestral Vision, Spell Snare, and other counterspells lets control decks draw cards very cheaply without getting behind early on, and that's powerful enough that we feel safer having it banned.
Modern is known for its efficient disruption spells, including Lightning Bolt, Path to Exile, Inquisition of Kozilek, and the aforementioned Spell Snare, that stop whatever the opponent is doing. These spells are critical for interfering with the wide array of strategies in Modern. A deck can never get enough of these cards, and that's why Snapcaster Mage has been so instrumental to the success of blue Modern decks. Ancestral Visions is a more efficient and more powerful source of card advantage, and it's going to replace or supplement Snapcaster Mage wherever it is found.
There have never been Modern decks with Ancestral Vision, so there are no Modern decks we can use as a template for our new Ancestral Vision decks. We can, however, look back to Extended, the precursor of Modern, to understand how we might use Ancestral Vision today.
The historic gold-standard Ancestral Vision deck is U/B Faeries. Filled with discard, counterspells, and creature removal, it's often looked upon as a control deck, but evasive Faerie creatures can quickly pressure the opponent, so it's at its best when assuming the aggressive role.
At Worlds 2009 I played a U/W Thopter Foundry-Sword of the Meek Control deck, and I lost to Yuuta Takahashi, a well-known Faeries expert, piloting this deck:
In 2011, Shouta Yasooka won the last Extended Grand Prix ever held playing U/B Faeries, and in 2014 he brought a similar deck to Pro Tour Born of the Gods:
Here's my new adaptation of U/B Faeries, using the previous two decks as inspiration:
Previous to Eldrazi taking over Modern, Grixis Control was the hottest deck in Modern. At Grand Prix Pittsburgh, Corey Burkhart impressed onlookers by using Jace, Vryn's Prodigy as a card advantage engine that hopelessly buried any opponent looking to fight fair.
Ancestral Vision offers even greater capacity for card advantage than Jace, Vryn's Prodigy but for less mana, and without being exposed to the liability of creature removal. Here's my take on Grixis:
Goblin Dark-Dwellers is especially exciting because, unlike Snapcaster Mage, it casts a card from the graveyard without paying its mana cost, so it can actually cast Ancestral Vision, which doesn't have a mana cost. Kolaghan's Command is essential with Thopter Foundry in the format, and with Eldrazi gone Affinity is sure to come back in full force.
The massive card advantage of Ancestral Vision can be used to forge new ground in Modern. It's hugely successful in Legacy as part of the Shardless Sultai deck, which combines with the most efficient disruption and threats in the format, many which are Modern-legal.
Abrupt Decay was completely taken off the map by Eldrazi, but it looks attractive in Shadows over Innistrad Modern. It's a maindeck answer to Thopter Foundry, and it's great against a format heavy with blue decks and counterspells that play permanents like Bitterblossom that must be destroyed. Scavenging Ooze stops the Sword of the Meek half of the Thopter Foundry combo, and it should prove useful against the upcoming increase in Snapcaster Mage.
The Modern version of Shardless Sultai must give up its namesake, Shardless Agent, and the ability to cascade into Ancestral Vision, but Snapcaster Mage will do just fine in the role of card advantage-generating creature.
Night of Souls' Betrayal is a fantastic permanent solution to Thopter Foundry, and it's oppressive against creature decks like Infect and even Affinity. Golgari Charm is another card that can sweep all Thopter Tokens.
Thrun, the Last Troll hasn't seen play in a while, but it remains one of the finest ways to beat control decks that rely on counterspells and removal.
Control decks haven't had a ton of success in Modern, and gaining access to Ancestral Vision will do a lot to make them viable. Control has had to learn to exist without high-quality card draw, and the most successful approach has been Jeskai, which has access the the most efficient creature removal in the format, Lightning Bolt and Path to Exile. It has been Modern's premier Snapcaster Mage deck, even using Restoration Angel to gain more value. It has fallen out of favor, however, and was mostly absent from the metagame last year. Ancestral Vision is right at home in a deck heavy with cheap disruption spells, so it will breathe new life into Jeskai Control.
Maybe the disruption red provides isn't necessary. A W/U variation offers superior mana and a gameplan centered around a robust creature suite:
When Treasure Cruise was legal in Modern, the most competitive shell for it proved to be an aggressive U/R Delver of Secrets deck loaded with cheap spells and creatures that filled the graveyard and could be readily cast when Treasure Cruise provided a wealth cards. Ancestral Vision is not so well-suited in this role, because these decks ideally cast a creature on turn one to start the pressure early. That being said, Ancestral Vision is powerful enough that it could make up for its slow speed. Before Treasure Cruise was banned, Pascal Maynard won Grand Prix Omaha with this deck.
Here's my update with Ancestral Vision:
Ancestral Vision isn't as fast as Treasure Cruise, so this deck is more oriented towards the late game and grinding. Goblin Guide drawing the opponent lands gives them card advantage right back, so I don't believe it's ideal here. I like the idea of Grim Lavamancer, which uses the graveyard that Treasure Cruise is no longer feeding off. Grim Lavamancer is at its best over a long game where it has time to operate, and it's a control card in the early game that helps buy time to reach the late game, so it's a great fit here.
Ancestral Vision will sit well with Thing in the Ice, which has received a lot of hype as blue's best new tool in Modern. It's similar to Tarmogoyf in that it's a robust creature, and it's like Young Pyromancer because it benefits from many spells being cast. Blue decks splash colors in part because blue creatures are weak, and other colors provide better options. Tarmogoyf has long-been jokingly referred to as the best blue creature in Magic. Actually being blue, Thing in the Ice offers the potential for a deck without a splash. If one color will get the job one, then playing more only reduces consistency. Here's how a mono-blue Thing in the Ice deck might look:
Bitterblossom and Valakut, the Molten Pinnacle were banned at Modern's inception, and since being unbanned they've each added depth to the Format without causing any imbalances. Ancestral Vision is a card with much deeper implications, and it's going to change the way blue Modern decks are built going forward. I hope I've shed some light on how Ancestral Vision can be used in Modern, and inspired some ideas of your own. Please share your thoughts in the comments, and I'll answer any questions!