It's no secret at this point that Jace, the Mind Sculptor hasn't lived up to expectations in Modern. Reactive decks have had a hard time finding a spot to land the card, especially against the top decks in the current metagame, Humans and Hollow One.
Sweepers should be good against both decks, since they seek to flood the battlefield with creatures. Unfortunately, most of the sweepers in Modern are either too expensive, don't answer large creatures like Champion of the Parish and Hollow One, or fail to answer the recursive threats Bloodghast and Flamewake Phoenix.
However, there is one sweeper which sidesteps all of these issues, and it's one that happens to pair beautifully with Jace, the Mind Sculptor. Yes, it's everyone's favorite Legacy staple and the bane of my existence for the better part of two years: Terminus. I'm not sure anyone in the world has put more creatures on the bottom of their library from that card as I have, so I'm going to try to get some of that value back today by switching sides and watching my opponent's shoulders sink as I flip over a miracle.
The rest of the deck is a typical control shell, although with Terminus being so potent it focuses more space on counterspells and even trims a Path to Exile. In the counter suite I particularly like Censor since it allows you to access a Terminus at instant speed by cycling into it on the opponent's turn. Irrigated Farmland shows up to do the same, as does Cryptic Command, which shows up in the full four copies, which makes sense given how Terminus can swing games if you stall long enough by tapping potential attackers.
Gideon of the Trials, a staple in U/W Control in Modern, does particularly good work here as a threat that forces the opponent to overextend into Terminus, as does Gideon Jura. Once Terminus resolves, they can start attacking and end the game before the opponent rebuilds their battlefield.
The one card I would be worried about with this list is Meddling Mage. You're short on ways to remove one naming Terminus, and between Cavern of Souls and Aether Vial, it's hard to prevent it from entering the battlefield. It's unlikely that they name Terminus in Game 1 unless they know the list, but it could be costly in the post-sideboard games once they know what's going on.
I saw some players try Terminus with Jace when the card was first unbanned, but that metagame was much less favorable for the sweeper with lots of Liliana of the Veil decks and G/R Ponza. Now that the metagame has settled around some creature decks, this strategy should be much better, and the pairing of a planeswalker that is very powerful but difficult to protect with perhaps the most powerful sweeper ever printed is a match made in heaven.