- Fuan is so far the only final boss (along with Hitori) that also appears as the midboss of the Extra Stage.
- She and Hitori appear on the cover of Autumnal Mythology.
- Fuan never appeared without Hitori in any projects.
- Not only that but Hitori appeared twice more often than she did in Nansei, he also get more different artworks and themes. This made fans say that Hitori overshadows Fuan in every aspect.
- Her name, Fuan (不安), can mean either "uneasiness", "unrest", "uncertainty", or "anxiety". Her last name, Satsujin, is the Japanese word for "murder".
- Fuan and Hitori are the only characters known to have last spells, along with Himeka Akaito (and Tsuzeru Kazemeri?).
- However, Fuan and Hitori don't have a last spell theme; Himeka and Tsuzeru do.