The March 2016 cover of CoroCoro reportedly reveals a brand new Pokémon called Magiana (マギアナ) that’s set to make an appearance in the franchise relatively soon.
According to Serebii, Magiana is a man-made Pokémon with a metallic body that initially came on the scene over 500 years ago. Also, the Mythical Pokémon Volcanion apparently knows a secret of Magiana’s and has been chasing the pocket monster for some reason or other — all of which will come to light in a new animated film featuring both of them. Given that CoroCoro’s been involved with several reveals in the past, it’s unlikely to be inaccurate beyond whatever might have been lost in translation.
Other than that, there’s not much definitively known about the critter. There’s no telling where it fits in the current Pokédex, what type it is or even what the official English name will be. There’s some speculation that Magiana is related in some way to Diancie, another Mythical Pokémon, as the two share a few similarities in their art.
Further speculation places Magiana as appearing in whatever game comes next in the series, with a Steel-type background in addition to whatever other type. It’s fairly unlikely that it’d be a singular type given its man-made nature. Then again, Mewtwo might disagree.