Up to four copies of a unique Pokmon card can be in your collection in total (so if you already have three, only one will be transferred), and just one copy of each ACE SPEC, Prism Star, Pokmon Star or part of a V-UNION card
Charizard GX - - HP 250 Type: Stage 2 Raging Out-GX Discard the top 10 cards of your opponent's deck
For control style decks, you get to disrupt whatever plans your opponent was depending on and as a bonus, you can make sure your next draw can also ruin their next play
Or you could use cards like Merfolk Looter and pitch big, splashy spells into the graveyard you can flash back for cheap, like Ezuris Predation, Clone Legion, or Insurrection
For the tutorial, this has been disabled