Ancient rivals awaken in the Pokémon TCG: XY—Primal Clash expansion!
After centuries asleep, the deep power of Primal Groudon-EX erupts from the land as Primal Kyogre-EX crashes in from the sea, riding titanic waves into battle! With colossal new arrivals like Mega Gardevoir-EX and Mega Aggron-EX, the Pokémon TCG: XY—Primal Clash expansion is alive with the primordial power of Ancient Traits—plus all-new Spirit Link and Special Energy cards! Let the earth shake and the oceans thunder, and get ready for a primal clash like no other!
Primal Clash and the Japanese equivalent Gaia Volcano · Tidal Storm feature Groudon and Kyogre in their newly discovered Primal Reversion transformation. Primal Reversion is an extension of the Mega Pokémon-EX mechanic, evolving from the long-standing Pokémon-EX. Each of the two Japanese subsets features 80 cards, with the expansion block released December 13, 2014. The English expansion features 164 cards and was released on February 4, 2015.
Included in the expansion are 12 new Pokémon-EX, including Mega Aggron-EX, Mega Gardevoir-EX, and the two Primal Reversion Pokémon. The expansion features a large amount of Pokémon with the Ancient Trait effects and extended artwork featured on the card.
The Japanese set has the notable feature of only including certain types between the two halves. Gaia Volcano features Fire-type, Fighting-type, and Metal-type Pokémon, while Tidal Storm features Water-type, Darkness-type, and Fairy-type Pokémon. The other five types are split between the two. This feature is lost with the English localization into one set.
The prerelease card for this set is Kingdra with its Ancient Trait.