Pokémon TCG XY Steam Siege Sealed Booster Box

Steam Siege, the tenth set of the XY series, was released in 2016 and is remembered as the expansion that introduced dual-type Pokémon to the TCG. Cards such as Mega Gardevoir EX and Volcanion EX combined two types on a single card, a mechanical novelty that gave the set a distinct identity within an already crowded era.

Alongside the dual-type experiment, Steam Siege carried the BREAK Evolution mechanic forward with Yveltal BREAK and Xerneas BREAK, and delivered a strong roster of EX Pokémon led by Volcanion and Magearna. The Full Art and Secret Rare cards of the set are among the most visually dense of the XY block.

Sealed English booster boxes from this period are increasingly scarce in untouched condition. This box retains its factory seal and the full complement of 36 packs, making it a candidate both for long-term sealed storage and for collectors completing the XY run in original packaging.