Hi! Thank you for your playing my game and new idea!
There are two problems. First. magic is used by only evils in the worldview. Second. it is hard to add new character and story to the story mode from now. I think many users will want whole stories for the new character. not only chapter 23 or some of the chapters.
I have two ideas of new characters. and I'm thinking of making them into "Sakura Blade 2". I cannot make it soon because I have already four plans of new other games. but I'll make it someday.
About new characters. see also SAK-Q14 and SAK-Q16 of the FAQ. You can access it from "Help" button in the app.