We've seen a resurgence of blue-based control decks in Modern since they have good tools to fight Grixis Death's Shadow along with new contenders TitanShift and U/R Gifts Storm. At the same time, U/B Control with The Scarab God is making some waves in Standard.
Well, it doesn't take long for Magic players to put two and two together and get four, or, in this case, Esper Control with The Scarab God in Modern.
For five mana in Modern, you need to be getting something that can take over a game with some degree of regularity and I think The Scarab God fits the bill. Outside of Path to Exile, no removal touches it. It rumbles with the big creatures around outside of Primeval Titan. And the ability lets you add more pressure to the battlefield when your mana isn't taxed by interaction.
That flexibility of being able to pass the turn and having your opponent know that you can still get value from your mana if they slowplay their hand to play around various removal or countermagic is huge. It generally forces your opponent to play more aggressively than they would otherwise like to. Control decks are uniquely positioned to punish these plays, so there's a natural, strategic synergy there.
Spreading Seas is a great disruptive element for a more tap-out-style control deck and happily takes the place of Remand here. Damnation, Detention Sphere, and Liliana of the Veil give the deck a lot of powerful, flexible removal so you're never without an answer, and Lingering Souls is one of the best cards in the format against Grixis Death's Shadow and Affinity.
There's plenty to like in this list and a good balance of threats, answers, and card advantage, much of which is tempo-positive. Going the traditional route of playing straight card draw spells has always been problematic in Modern, since discard can strip those spells away, and taking the time to cast them is a significant risk. This deck can gain the necessary card advantage to win attrition games without losing tempo, between its sweepers and the fact that every threat in the deck has inherent card advantage.
After years of complaints about the lack of control decks in Modern, we may be up to three viable options at the same time. I bet Shaheen Soorani is smiling.