Unown G has returned to the meta! Well, sort of...
Glad to see that, like Golduck Break, it isn't type exclusive (there are way too many cards like that; this is what causes some Pokémon types, such as fighting, to become extremely broken in terms of support).
Nice artwork too. Not sure if the tower in the background has any relevance...
I just realised: this makes Jolteon, Glaceon (and possibly Espeon) -EX decks even more powerful than before.
Personally, It is my belief that even though Magearna wasn't in X and Y (nor could be found through hacks), it is still a Gen 6 Pokémon. Something about the design, the feel, the whole kinda-looks-like Diancie thing...
I also assume that it will be available, with Zygarde Perfect and 10%, either next year in a second round of X and Y era games, or (what I'm really hoping for) is that after you beat the Champoin of Alola you can head off to explore Kalos and find both Pokémon hidden there. I mean, I don't have too much of a problem with just getting the Pokémon, but I feel like after scanning the code/putting in the password/other it would be better to actually meet Magearna as part of a Post-game additional story.
If Magearna is Gen 6, it will be after Volcanion in the Pokédex. As a Gen 7 Pokémon, I still assume this number to be the same.
Either way, really neat card!