A Torch usually becomes a Mystes by random chance, and the process happens the instant that human becomes a Torch. Most of the time, the Torch does not become conscious of the Treasure Tool residing inside them, even when the individual dies. At the death of a Mystes, the Treasure Tool travels to another human who has just acquired their Torch status and this process of transferring a Treasure Tool from one Mystes to another goes on until the Treasure Tool is extracted from the body of the Mystes.
Because of the equally volatile nature of Torches and Mystes, the latter are generally discriminated against by Flame Haze and Crimson Denizens, as they are seen as mere Torches with a few extra abilities.
The Mystes that have been seen over the course of the series are:
- Yūji Sakai (current bearer of Reiji Maigo)
- Tenmoku Ikko ("Monster Torch", creator of Nietono no Shana)
- Johann (Creator and former bearer of Reiji Maigo)
- Name Unknown (Bearer of Papagena, the girl Mare is using Kisei on)
- "User of Grotesque Chakram" (bearer of unspecified Treasure Tool)
- The term is probably derived from the Greek word μύστης (mystēs), which means "a person who has been initiated", in the sense of "initiated into the world of the Crimson Denizens and Flame Haze".
- In Episode 01, it had been demonstrated that Mystes don't bleed, however, in Final Episode 13, when Shana cuts Yūji's forehead, he is shown bleeding.