Knowing that the Sailor Moon cast has their own past life plot going on in this AU, I'm just wondering what the specific limitations are in regards to that for other characters from other canons that have canon past lives that are important to their history?

It wouldn't be from the Savior-era, at least not if left similar to canon, but I'm not sure what is or isn't acceptable.

Also, if a character was a Zorua shifter, would they be able to use the Illusions ability in their human form, too? If so, would it be restricted to illusions on themselves? This character had, in canon, made a body double illusion for a time, so... as for the detail that 'can't be hidden', like Zorua's tail, I was figuring in this case it would be the distinctive hairstyle--he has the same look, though in a different color, in another form he can take in canon.