For the release of Triplet Beat, there will be a special 'Sealed Battle' tournaments at participating Pokémon Card Gym stores starting from March 10 2023.
These are small 'prerelease' like tournaments which consist of 4 players in which you have to 15 packs of this set and make a 40-card deck with them. These appear to be similar to the Lucario VSTAR HR Competition but less big.
The winner & the Rock-paper-scissors Tournament Winner gets a Sealed Battle Promo Card Pack which consists of either 1 of 2 Koraidon or Miraidon promos, these are promos with 'Art Rare' illustration seen from past sets.
We are getting these promo cards in our Scarlet & Violet Elite Trainer Boxes.
Everyone who participates also receives a 1 our of 2 random Nemona promo card and Rare Candy promo card.