Its likely that a set of these promos was distributed to all participants of either the main official tournament, or to participants of the Neo Prerelease League
The key differences are print quality (Japanese cards feature enhanced embossing and premium texture), market pricing (EN top cards often trade higher due to smaller print runs), and tournament legality (each version is only legal in its respective regional events)
And thats not all: remove flying counters from your creatures placed on them by Luminous Broodmoth, slow down the aging of Cumulative upkeep cards, like Mystic Remora (or Blizzard, if you feel like putting flying counters on opponents creatures like a monster), allow Undying creatures to continually un-die the (giant robotic manta in the) skys the limit
Urza, Lord High Artificer Weve looked at commanders that cheat cards into play, weve looked at commanders that produce mana, and weve looked at stax commanders that break symmetrical effects like Static Orb