The Mystian System is a gender system, one of the four gender systems in the Nature Systems, which describes genders related to different mystical and/or magical aspects and qualities of nature, and it is unique in that it is not aligned with any specific aspect of nature but instead is just aligned with magical aspects of nature. Because of that, genders in this system can be used as genders on their own, but also as descriptors for genders from all of the Nature Systems, not just its own. For example, if someone felt that their gender was related to peaceful nature magic and daffodils, they could use the mystian gender 'paxean' (a gender related to peaceful, calming nature magic) and the fleurian gender 'daffodilian' (a gender related to daffodils and their qualities) to describe their gender. The Mystian System consists of genders related to some aspect of natural magic, including genders like cavernian (a gender related to obscure, shadowed nature magic) and vevesian (a gender related to chaotic nature magic).
Since genders in the Mystian System can be used to describe any gender related to nature, they can also be used as modifiers for nature-related genders that aren't part of any of The Nature Systems. For example, treegender is a floragender but is not part of any of the Nature Systems, but due to its connection to an aspect of nature, any mystian genders can still be used as modifiers for it.
The Mystian System is only for magic-related genders that are also nature-related, so not everyone whose gender is magical could identify with the system.
History
All the terms and flags from The Mystian System were coined by FANDOM user Reign of the queerios throughout the month of February 2021.