We're starting to know a considerable amount of the cards.
Ponyta, Rapidash, Bagon, Shelgon, Salamence, Dratini, Dragonair, Dragonite, Staryu, Starmie, Holon's Magnemite, Holon's Magneton, Metagross*, Groudon*, Kyogre*, Ditto, Ditto, Ditto, Ditto, Ditto, Ditto, Pikachu, Raichu, Zubat, Golbat, Crobat, Rayquaza, Mewtwo, Latias, Latios, Eevee, Flareon, Flareon ex, Jolteon, Jolteon ex, Vaporeon, Vaporeon ex, Ralts, Kirlia, Gardevoir, Holon Energy SYN GL, Holon Energy SYN WP, Holon Energhy SYN RF, Holon Scientist, Holon's Poké Ball, Dark Metal Energy.
^ edited.
Not all confirmed but more than likely based on what we know.