The official website, explains this, and no I havent tried it myself
This is a collectible product
However, this is only when they are challenging another character, not just more strength across the board
Snorlax Doll Trainer HP120 Item If this card is in your hand when you are setting up to play, you may put it face down in play as if it were a 120 HP [C] Basic Pokmon
its a versatile Eevee ex that fits nicely in various decks
The rarer cards do cost more Pack Points (up to 2,500 Pack Points) so its not a viable way to master the set unless you have 1 or 2 cards left, however if youre looking for a card to complete a deck (such as Gardevoir or Hypno which are popular at the moment), it can be a quick way of doing so