Aquanort

Well, this and the next ones to follow up have been done around the time where Birth by Sleep had been freshly released and the whole circumstances behind the very villainous scientist/Keyblader Wielder/Master known as Xehanort had been revealed at long last (with lots of other shocking discoveries to follow up ever since).

Since said main bad guy had been one old coot and had been in need for a new vessel to survive in order to see his plans reach fruition, he'd do so with a male-counterpart which he'd let succumb to the darkness before possessing him.

This is the result if he had just taken a different approach and had been going after the female main heroine instead.

However, those, independently if good or not, this and the ones to follow happen to be simply edits to showcase how each character would look like when being possessed by Xehanort starting with Aqua...