It's no secret at this point that Teferi, Hero of Dominaria is one of the best cards from the new set. It has completely shifted Standard control decks away from black as the primary support color and towards white, while also helping to elevate Jeskai Control to a breakout performance in Modern last weekend.
The ability to untap a couple of lands on the turn you cast it and hold up a piece of interaction makes it much easier to start the planeswalker snowball rolling down the hill. However, in order for that sequence to work, you need quality removal at two mana, which white previously lacked. But with Seal Away riding alongside Teferi in Dominaria, that issue was remedied, leading to a clear pairing in the early weeks of the format.
But if there's one constant in Magic, it's change. Players learn quickly how to react to the top decks, and when it comes to Seal Away, the reaction was clear. Vigilance threats like Heart of Kiran and History of Benalia have seen significant play, as have Disenchant effects to undo the enchantment-based removal in U/W Control.
It's time for control players to react, and that means a return to the red removal we saw dominate last fall. Magma Spray, Harnessed Lightning, and Abrade are all available after a Turn 5 Teferi and together form a removal suite that can handle all manner of early threats. The mana is workable with the new multicolor lands and Aether Hub plus Glimmer of Genius for more energy, and you can splash Cast Out along with Teferi to have a nice catch-all at the top of the curve.
The main loss here is in the white sweepers, Fumigate, and Settle the Wreckage. Hour of Devastation is a nice facsimile and the ability to answer planeswalkers will sometimes be a benefit, but not handling large creatures and acting as a liability when trying to defend your own planeswalkers is rough. Still, with more cheap removal and spot removal that can handle large creatures, the need for sweepers in this list is much lower than normal.
The red splash also allows a sideboard juke towards a more aggressive plan with Whirler Virtuoso and Torrential Gearhulk. I particularly like Virtuoso since it requires a sweeper to answer completely and doesn't run into Negate in control mirrors like History of Benalia.
It's time to start branching out in Standard to fight the top decks, and while this deck isn't trying to reinvent the wheel, it makes some nice innovations for the current metagame.