This was quite literally the original TCBM (known as Trading Cards by Mail amongst the Pokemon Community)
The Pokmon Center Hiroshima Special Box, for example, was sold only at that location and remains highly collectible
They also are receiving a new boss monster in Ultimate Dragon of Pride and Soul (YGOrg Translation) , a Level 12 Fusion of 3 monsters with 2500/2500 that gains 4500 ATK/DEF when you have 25 or more cards in GY, plus it can destroy all cards the opponent controls if they have 25 or more cards in GY
The primary ability of the card is unlocked when you tap the card and remove three charge counters, and gain an extra turn
Depending on the card rarity, it could provide more pack points if the card exchanged has a higher rarity
That was before the war camebefore the fight for the Multiverse devastated Eulas home, and with it her hopes for a magical education