Looking at the card might be a head-scratching nightmare, but on Gatherer, theres a simple explanation
Outside of Standard, noncreature spells are typically the toughest for control to deal with, making Dovins Veto and Duress effects great
Milling enough cards to allow Emet-Selch to transform isn't tricky, once you've done that, you just need to keep them safe for a round, and then you can use the tools in your graveyard to bring the game to a decisive conclusion
Many of the cards in the top 20 are Japanese showcase cards that can be found in Collector Boosters
I also saw some intriguing cards around the room: the person next to me opened a Mana Drain, which had been revealed to much excitement at the panel
Then again, according to a lot of players Ob Nixilis, The Adversary doesn't really need any help