Jump this week reveals Milla Maxwell, the original Milla from the first Tales of Xillia, is set to return in Tales of Xillia 2.
[Warning: the follow description may be considered spoilers for the first Tales of Xillia. I'm not sure, honestly, but read ahead with caution.]
Nothing has changed about Milla. She is still herself. The same Milla who saved the world with Jude a year prior to the events of Tales of Xillia 2. She is the current Lord of Spirits, a title which she inherited from earlier generations of Maxwells.
Thanks, Tale Tale Source.