There is no deck out rule
"TVTV" ["At that time, there were no magazines that explained video game strategies
Often you need it for it's high toughness, but other times, you want to find your game changer in Rhystic Study, or impactful cards like Emry, Lurker of the Loch or Windfall
3 - Charizard ex (Full Art - 215/197) Without a question, this is one of the rarest cards in the set, and its other variants will complete the Top 3, as it is no mystery: "once a Charizard, always a Charizard." But this Charizard isn't here only due to its collector's value, as it is also a very interesting card for the competitive format, which is something so rare it happened for the last time at the Sun/Moon: Unbroken Bonds era, with its Tag Team card
The one extra mana in its cost is insignificant when you consider the extra card advantage