User blog comment:ArcOfRuin/Would writing a story based on Tsukurogami be accepted here?/@comment-24101790-20180315205638

The spinoff rules were created more for setting up a check system for people using other intellectual properties (for example: a lost episode pasta about the Simpsons). As such, it doesn't really prohibit the use of myths, cultural creatures, etc. as long as they're up to the site's quality standards. That being said, this wiki does tend to favor originality in its story-telling so I'd be wary about falling into a pattern or following overused tropes.