Day's Undoing and Sundial of the Infinite are the only cards from the list where the end the turn effect cant be used to end your opponents turn under normal circumstances
Misty is also vital for this deck, allowing you to stack several energies onto Dragonite or Articuno to get an early headstart
You dont have access to these in the few decks that dont run white, but those tend to have their own built-in wincons
A little preparation goes a long way in boosting your final grade
That being said, the mechanic has recently gotten a ton of support, so much that we can build a whole deck around it
It was also the end of staple cards, such as Lightning Bolt and the beginning of the end for Counterspell, two extremely powerful and simple cards, one a Red common, one a Blue uncommon