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.