Battle Fantasia is open to entirely original themes! They can be fleshed out in the character application, where we ask for, at the minimum, a one paragraph introduction that we’ll post on our Theme Primer, and on the game within +casts. Original themes are expected to be tasteful, and they need to be themed to the game's genre (magical girl), which we help guarantee by making sure original themes follow the guidelines set out in our Paths to Power files: in short, all characters have some sort of vital Artifact, and may also have a Contract or Legacy that is a part of their destiny.
Making a new original theme is a pretty major undertaking, comparatively speaking; it sets the approval bar higher, since not only does the new character have to fit the game, but the new theme itself also has to fit the game. Often the application process includes requests by the staff to establish more details about original theme antagonists ("who will the opposition be? what are their goals?") and about the off-camera history of the original theme within the larger setting of the game, before the character was even born. It's a lot of extra work, to say the least, but it's done with purpose. We strive for every original theme to be deeply integrated in the setting and ongoing events of the game, as much so as all the other existing themes; therefore the new original theme needs to be pretty thoroughly developed, almost like a pitch for a new cartoon on Magical Girl Network.
For this reason, we recommend that a new player's first character be from a theme that's already on the game; that way they can start playing as quickly as possible. Then, they can develop the original theme of their dreams at their leisure, without feeling like all the extra work is preventing them from joining in on the fun. If new players are determined to start with a new original theme, however, the staff will do everything in their power to make the process as quick and fun as possible!
Original characters applying into existing feature themes can view the guidelines at Theme Guides: Original Characters. Original characters applying into existing original themes should get in touch with the player who created the theme in question -- the staff is happy to help make introductions.
For more information, please see: Rules