It kind of bothers me a tiny bit that certain classes have been merged or erased. So I would suggest bringing back the Fire-class, I mean, there's at least 3 already in existence (Anwyn, Hestia, and that orange one owned by Ama). Also an Ice-class would be cool, since Noel is classified as Ice-class.
As for entirely new classes, I have a couple ideas. Techno-class (digital/technology based) Dragon-class (although, could me more of a sub-species)
I also have ideas for how to trait all the classes I mentioned, if you're at all interested, you can note me. ^^