Storm Emeralda Lands in Japan July 31: Mega Rayquaza ex, Split Stadiums, and the Road to Delta Reign
Japan's M6 expansion is built around the return of Mega Rayquaza and introduces two-part Stadium cards. Here is why the July 31 set is the cheat sheet for November's English Delta Reign release.
The Sky Serpent Comes Home
Japan gets the next big Mega Evolution moment on July 31 when MEGA Expansion Pack M6: Storm Emeralda arrives, and it is built entirely around the return of Mega Rayquaza. The set runs 76 cards in the main list plus an estimated 35 to 40 secret rares, and it is the direct source material for the English-language set collectors already have circled: Mega Evolution - Delta Reign, launching worldwide November 6.
Mega Rayquaza ex: The Card
The chase is Mega Rayquaza ex, a Colorless, 280 HP basic with the Champion's Roar ability - play it to your bench and you may look at the top four cards of your deck and attach a basic Energy you find there. Its attack scales with Fire and Lightning Energy attached across your board, an echo of the Emerald Break era deck that made Mega Rayquaza one of the most beloved competitive cards of the XY block.
Nostalgia is doing real work here. The 2015 Mega Rayquaza era remains a high-water mark for a generation of players, and vintage Rayquaza cards have been among 2026's best performers - Rayquaza VMAX from Evolving Skies was still climbing double digits this month before Storm Emeralda even hit shelves.
Split Stadiums: A Legend-Card Throwback
Storm Emeralda also introduces two-part Stadium cards that combine into a single image, a mechanic that deliberately recalls the fan-favorite LEGEND cards from the HeartGold SoulSilver era. Multi-part cards have historically graded and sold well as matched pairs, and completed split Stadiums in high grade could become a quiet sleeper chase once the set matures.
How Japanese Buyers Should Play It
- Preorder pressure is already high. Japanese sealed prices on recent Mega Evolution sets have spiked at release and cooled within weeks - patience has been rewarded all year.
- The SAR and secret-rare Rayquaza cards are the long-term holds. Japanese first-print chase cards from sets that later headline an English release have a strong track record.
- Delta Reign will not carry everything over. English sets remix multiple Japanese sources, so some Storm Emeralda cards may stay Japan-exclusive - historically a recipe for late-breaking price jumps.
The Road to November 6
The teaser trailer for Delta Reign confirmed Mega Rayquaza ex as the western flagship, with Gallade and Eevee also featured. Between Pitch Black this Friday, Storm Emeralda in Japan on July 31, and Delta Reign in November, the Mega Evolution era now has its full-year arc mapped - and Rayquaza is the endgame.
Every Mega Evolution set so far has taught the same lesson: the Japanese printing tells you what the English chase will be four months early. Storm Emeralda is the cheat sheet for November.