Even though her songs are meant to scare and confuse humans, in many fan works she is depicted happily singing with a graceful voice, sometimes viewed with a microphone. It is also common to find her alongside the Prismriver Sisters in fan works, where the four makes up a band in which she serves as the main singer.
In fan works, she is often seen with other lower level, childish characters such as Cirno, Rumia, and Wriggle, making up Team 9.
In some fanworks Mystia appears to wear a brown yukata with the sleeves rolled up as well as a blue apron and kerchief, and described as a keeper of street stall. This version of Mystia is often called Okamisty from a Japanese word "Okami" which means female shopkeeper or chef of traditional pub. It has not appeared in any official work except brief article of Aya.
In some fanworks, Okamisty and Mokou appear to have a romantic relationship, but somehow, Mokou's job is being described as a charcoal maker, even if her real job in official works is the guide of Bamboo Forest and the owner of Yakitori street stall.