When we think of Grixis Control in Modern, Corey Burkhart's name immediately comes to mind. He's been the primary champion of the deck for a long time, and his removal- and Cryptic Command-heavy list is the go-to for anyone looking to play that shard.
But it appears a new challenger for the Grixis crown has emerged. The same player has taken their own spin on the archetype to two separate Magic Online League trophies, and, well, they have some different ideas about how the deck should be built.
To start, this list has a lot more creatures. A full three copies of Pia and Kiran Nalaar provide an easy way to stabilize the battlefield against small creatures or pressure removal-heavy decks with a threat that demands a sweeper.
We also see three copies of Jace, Vryn's Prodigy to supplement the Snapcaster Mages. Though Jace doesn't play well with counterspells, it does provide a nice way to recast your other disruptive spells, and its ability to control the battlefield is more valuable with the rest of the creatures in the deck.
Next up is my favorite card in the deck, Nimble Obstructionist.
As someone who played a lot of Legacy when Temur Delver was a top deck, I know all too well the pain of having your fetchland targeted with Stifle. I can only imagine how bad it feels when your opponent is also drawing a card. Naturally, I want to make that happen as much as humanly possible.
Of course, there are plenty of other viable targets for that ability, from Kitesail Freebooter to Oblivion Stone to opposing Snapcaster Mages. It's not an effect that's overpowering in most spots, but it'll be the only card that can save you in plenty of situations, and the ability to flash it in as a 3/1 flier means you can shift to an aggressive posture if your opponent goes out of their way to play around the Stifle.
With all these creatures, I like the singleton copies of Liliana, the Last Hope and Liliana of the Veil. Both are threats in attrition games that can also affect the battlefield, further cementing this list as one that can win in many ways. Trying to find the right balance between the aggressive elements, removal, and counterspells is certainly tough, but from its results, it seems like this list is at least on the right track.