I have a few ideas:
1. I think that there needs to be some kind of post explaining what each of the user groups mean. (ie. Where that species mainly dwells. How do they come about (are they born, or created? can someone be half that species and half another, etc)? Are they immortal? Do they have long lives, but do die of old age? Or is their life the same length as humans? Do they have special powers, etc?)
2. Perhaps somewhere explain a little about the Bladed Hearts School.
I'll add to this when I think of more. Thanks!