As Hecteyes's ability resolves, the next opponent in turn order (or, if it's an opponent's turn, that opponent) chooses a card in hand without revealing it, then each other opponent in turn order does the same
It's an incredible pump effect, and because it's attached to a creature and not an Instant or Sorcery, you can find it using green's excellent tutor effects
We actually wanted to give you a little bonus for making it this far
Standard: Only cards from the latest block can be played (typically, cards from the last 2 years)
At ~$100/box with four guaranteed Radiant Kanto Pokemon and a ~20% chance per box of any SA, S10B offers one of the most reliable EV floors in the Sword & Shield era
More aggressive decks might make use of the Tomb of Annihilation, since it drives down both players life totals and resources with the rewards of a 4/4 with deathtouch at the end