EX Crystal Guardians (Japanese: きせきの結晶Miracle Crystal) is the name given to the third expansion of cards of the Delta Species era of the Trading Card Game. It is also the fourteenth EX Series expansion.
EX Crystal Guardians reveals another new area; a mysterious island, far from the city of Holon, which is a place where Pokémon, both regular and Delta Species, live in harmony. The island also bears naturally growing crystals, which are said to grant special powers if used correctly. These crystals form the basis of many of the set's Trainer cards: Cessation Crystal, Crystal Beach, Crystal Shard and Mysterious Shard. The set includes cards from the Miracle Crystal expansion as well as from the set's two Japanese half decks.
Sceptile ex δ, the first Delta Species Pokémon-ex debuts in this set.
A special third theme deck, Earth Shower, was released exclusively in Wal-Mart stores in America, making this the first expansion to have three affiliated theme decks in the TCG. The theme deck was released commercially in the United Kingdom and Europe. Diamond & Pearl would later feature three theme decks, as would Great Encounters and HeartGold & SoulSilver. Another set with three theme decks is Black & White.