Hero Fighter Story Editor is a program that is used to make custom stages that can be downloaded and played by everyone. The game's stages are written in XML format, which is a format that the HF code can parse and interpret. It works similarly to LF2 Data Changing for those who know about it. You will be able to download XML stage files and generate the custom stages. The editor will let you save the custom stage as an XML file (so you can continue working on it later) and will generate an EXE file that will replace the story in the original game with the stage you made. The editor is still very basic but does the core job.

To show proof of results, here is a custom stage made in the past by @Verdusk. The stage's "story" is that you are fighting the 3 biggest and strongest clans of the time that this was made in. The stage is fairly challenging, and is pretty long, but is still entertaining and exciting.

Hero Fighter War Stage (Click To Download)