i'm still big on the 'lucina joker' concept, i.e. a more consistent version of joker that deals more damage on her own but receives a much smaller power boost from her persona to compensate - reason being that, as far as i see it, her longer sword and rifle imply an inherent power/range upgrade from joker's dagger and pistol, so cendrillon would need her power reduced in turn to maintain an overall balance between joker/kasumi.
as it stands, there's not much else that needs changing. i previously considered joker's up-tilt to be incompatible with a longer sword, but she does the exact same spinning trick in her character trailer (right at the start in the casino cutscene), so that's not a problem. joker's physical attacks are all kick-based, which--as if by magic--is kasumi's entire thing as well. as for the recovery problem, just as arsene's up-B attaches his wings to joker, cendrillon's can attach her cape to kasumi.
the only thing i'm really curious about is the implementation of kouha/kougaon over eiha/eigaon, both in function and animation. eiha/eigaon's animations from P5 are captured almost perfectly in smash and translate easily to an arcfire-type ground projectile, but kouha/kougaon take the form of holy spikes surrounding the target in the air, so a 1:1 conversion wouldn't be visually (or mechanically) the same. unlike curse moves, bless moves also have no precedent for slowly draining HP, so it's a bit of a mystery what kouha/kougaon would do besides maybe instant but lesser damage (in keeping with the whole 'simple/lucina joker' thing that allows for more straightforward plays).