The structure first. Storm Emeralda's main set runs 76 printed cards (numbered 001–076): 38 Commons, 25 Uncommons, 8 Rares and 8 Double Rares — the Double Rare tier being where the set's eight ex Pokémon live, including all four Mega debuts. Above the printed total sit 37 secret numbers: 12 Art Rares (077–088), 18 Super Rares (089–106, including three gold Special Energy cards), 6 Special Art Rares (107–112) and one Mega Ultra Rare (113). Add the alternate "Set of 2" printings of the three split Stadiums and the physical checklist lands at 116 cards. If rarity tiers are new territory for you, our rarity symbols guide covers how the Japanese tiers work.
The product itself follows the standard Japanese formula: 30 packs per box, 5 cards per pack, ¥200 per pack (¥6,000 per box at MSRP). Distribution is the story of the year, though — like other recent MEGA-era sets, initial supply moved through store lotteries and allocations rather than open retail, which is a big part of why aftermarket box prices opened far above MSRP.
Thematically, this is the Emerald chapter of the Mega era. Where M5 Abyss Eye went dark with Darkrai, M6 goes up into the stratosphere: the checklist is built around the Hoenn weather trio and the sky-dragon lore that the Emerald generation told best. Kyogre and Groudon appear as printed Rares with Art Rare encores, the three split Stadiums are literally the trio's homes — the Marine Trench, the Summit, the Lava Tube — and the Trainer roster (Zinnia, Aarune, Tate & Liza) reads like an ORAS cast reunion. It is a coherent, affectionate set design, and collectors have responded to it.
One structural note worth internalizing before you read the card-by-card commentary: this set's value is extraordinarily top-heavy even by modern standards. Of the 116 cards in the snapshot, the top two numbers — the MUR and the Rayquaza SAR — carry roughly two thirds of the set's total market value. Everything below the Special Art Rare tier is, by chase-set standards, affordable.