Anduin DK is probably what will break the set, eventually. Priest has so many good cards, and Anduin + Raza is virtually impossible to beat if the board state is about even when it happens. Combined with solid cards that can enable priest to last until that point, you basically need to combo them to death, or splash mindbreaker and rely on them not generating a board or having pain/dragonfire/any removal in their hand.
Like, I had turn 5 discard portal out and Raza Anduin still kept stable until turn 8, where he proceeded to make my portal mean nothing. He lasted through 4 turns of two free 3/2s, 32 damage worth of imps, and extra from my other cards.
As I sort of expected, DK Mage and Pally, while strong cards, are finding out that face is still the place and druid is still cancer that will kill you by turn 6. Day 1 OP never prevails against smorc.