From Bulbapedia, the community-driven Pokémon encyclopedia.
Epic Collection is the name given to a special set of cards from the Pokémon Trading Card Game released in 2007 in English and possibly European and Japanese languages. The set is quite unique as it contains only 3 theme decks, no set logo and seemingly no cards of its own, and as such no boosters have been made for it.
This set's three Theme Decks are based on each of the Generation II starter Pokémon evolution families, and contain both that family and their Generation III starter counterpart. As stated, the Epic Collection contained no cards of its own and instead used cards from EX Deoxys, EX Emerald, EX Unseen Forces, EX Holon Phantoms, EX Crystal Guardians, EX Dragon Frontiers, and EX Power Keepers to build each of its theme decks.
This set is rather difficult to place due to lack of official information but it had a 2007 release and due to it containing EX Power Keepers cards it must have been released after EX Power Keepers, but before Secret Wonders as that set was released in 2008.
English Theme Decks