I can see Cruella in either Radiant Garden or Disney Town. I say Disney Town because of the boss fight some people are suggesting for her. With her car/a car heartless. Then if Sora can change his Keyblade into a vehicle type thing that TAV can do, then just throw that fight on the racetrack and....BOOM you got yourself a boss fight.
EDIT::
Cruella boss fight idea.
Have her driving in her car, fighting alongside the car Heartless from KH2.
EDIT::
Cruella boss fight idea.
Have her driving in her car, fighting alongside the car Heartless from KH2.