Alright, please forgive me as I mean not to come off as harsh.
The app is incredibly bare, and personally I don't like it at all, especially the history, and as a sin character we feel that they require a personality that describes them as said sin as opposed to "oh you know, envy." The history is alright in the regards for explaining how the character became envy to begin with, but it needs more explanation on what was their life was poor, you can do better. The abilities are bare and incredibly limited, and unless you want to go with this I advise you put some thought before you finalize everything.
So all in all, this app needs great improvement, please try your best to elaborate on every detail possible, such as soul requirement for abilities if have any. And remember, if you need any help I and others are happy to oblige.