If it's KH related, I really hope it has "III" after the name, or else I'm gonna be sad. I think Nomura said there was going to be three other games (or three games that told stories of Mickey, Roxas, and Riku, I honestly can't remember) and Versus before KH3, and KH and KH2 were 4 years(?) apart with one game in between, and it's already been 5-6, so here's hoping it's KH3!
Actually, it isn't just that the device powered her, to go more into it, the devices contained Sora's memories of the worlds that he was in, and his memories of him. Like for example, Xion gains the ability to fly in Wonderland, maybe thats an adaptation of glide, and she uses Sonic Blade as her special. For a better example, in Agrabah, she has 4 swords, reference to Kurt Liza, and she uses Ars Arcanium (Don't really know the spelling) as her special, direct from Sora's memories.
In the organization, she was created as a clone of Sora, she was made to absorb Roxas and become the new keyblade master, doing so she needed to defeat Roxas to absorb his power before he faded away I'm guessing. If she did absorb Roxas, Sora would never wake up, and Xion would be their #1 to help them collect their hearts, which means that no one can stop them, and they don't need Sora to get their hearts. However, when Xion failed, she faded away, giving her power to Roxas, which explains his Duel Wielding, then it all goes to KH2.
This information was pretty good to read, liked to learn about it.
But I was kinda disappointed at how many spoilers I saw up there with no warning what-so-ever when I read it...
At least finding out what each world has to offer is still a mystery to me :D
Man, I watched the first 10 seconds of it just so I don't spoil it all for me, and it looked pretty good. For some reason the place where Terra and all are from reminds me of Radiant Gardens, like the wall they were sitting on was a wall in the Hallow Bastion Postern. I really can't tell because of first 10 seconds and all.