The exciting new leak shows us that not only are we getting phenomenal full art secret rare cards, thus meaning we're getting more than the initial 34 cards, but we're also seeing the return of Team-Owner Pokemon with their own small gimmick to their playability that is an homage straight from the ADV card era -- to the letter! The cards are Team Aqua's KyogreEX and Team Magama's GroudonEX, and feature gorgeous artwork with the Aqua and Magma admins, complete with their signature Pokemon, attacking alongside their respective legendaries.
Given these are SR cards, they're most likely 035/034 and 036/034 in the set numbering, but at the moment they're too hard to decipher and it's likely these might not be the only secret cards in the set either. It also seems like these have a lovely glossy holo treatment if the preview image is anything to go by, likely as a result of these not having the embossed foil of most standard SR cards. You can check them out below!
Many thanks to the Japanese PTCG fanbase for their quick transcriptions, which made it possible to translate these.