As I see it, their biggest vulnerabilities are: Their win conditions An overreliance on counterspells (despite the fact that Teferi, Time Raveler is the most important card in the mirror)
Start by removing several low-impact items and combat trick-style actions like Stolen Schimitar, He's Got a Sword, Viscious Betrayal, and Steal From the Rich, and replacing them with more extra copies of Pongo, Ol' Rascal
On the left wall, between the windows, is where the big-screen TV will hang
Neobrand is realer and scarier than it ever was last year
Delney, Streetwise Lookout, a mythic mono-white legend from Murders at Karlov Manor, lets creatures with power 2 or less get in on the fun, doubling not only any 'enters' triggers they may have, but any triggered ability they possess
Queza, Augur of Agonies can similarly amplify Extorts potency when partnered with cantrips, in particular