Until the end of your next turn, you may play those cards
You can tell the rarity by the number of straight sides the icon has: the more straight sides, the rarer that card, starting from the circular common up to the pentagonal legendary rare
It's also a good resource for figuring out how much your cards are worth once the new set is out, so if you pull any Surge Foil cards in your booster pack preorders, you might suddenly find yourself with quite the nest egg
This deck has some interesting decision points and isn't a linear strategy, but it's also not the most complicated out there - and that's important for a beginner deck
Wilds Unknown is available for prerelease on May 8, and everywhere starting May 15
The fact that you can play the exiled cards as long as you control Lightning is a nice bonus, but the lack of Haste here really kills the card, in my opinion