RE: Will Zygarde have an alternate form?
Most likely a Mega Evolution...
Its the newest mechanic so it's the perfect excuse to give it a new forme while also not feeling repetitive compared to Giratina and Kyurem, plus its BST is 600 while Xerneas and Yveltal's are 680. Mega Evos increase their BST by 100 points, so a Mega Zygarde would have a BST of 700, effectively letting it surpass the other two by 20 points (just like Kyurem), and also tying with its role as the balance between Xerneas and Yveltal (similar to Rayquaza).
Finally, like others said, that would explain its X dex entry as Mega Evos were advertized as transformations that occur when a pokémon unveils its true potential or something like that...
Most likely a Mega Evolution...
Its the newest mechanic so it's the perfect excuse to give it a new forme while also not feeling repetitive compared to Giratina and Kyurem, plus its BST is 600 while Xerneas and Yveltal's are 680. Mega Evos increase their BST by 100 points, so a Mega Zygarde would have a BST of 700, effectively letting it surpass the other two by 20 points (just like Kyurem), and also tying with its role as the balance between Xerneas and Yveltal (similar to Rayquaza).
Finally, like others said, that would explain its X dex entry as Mega Evos were advertized as transformations that occur when a pokémon unveils its true potential or something like that...