Unlike other games, there is no grade shop, and the hardest difficulty (unknown mode) comes from a DLC instead of a clear save.
Anyway, this is still useful, as much like Xillia 1, Unknown Mode seems to be balanced around the player enabling x2 damage mode.
That causes players and enemys to both deal double damage. Without it, enemys have some absurd HP numbers, and aren't very lethal.
You can optionally carry over lvs, skills, artes, etc.