You kill their creatures, counter their cards, and delay the game long enough until you have the ability to kill your opponent with a single card or combo
That's great on its own, but Gyome also lets us pay to sac a Food token and grant a creature indestructible for the turn (at an additional cost of tapping it, like the way the troll mechanic Regenerate used to work!)
Hopefully, this overview has helped kickstart your winding journey of preparing for the tournament
Yet, in a vacuum it still works, because the card draw worked in the natural play of the game
it is handling the buying question as an operations problem: tracked shipping from Tokyo, destination and customs details, quantity briefs, substitutions, sealed/PSA condition rules, and support before payment