Crystagender is when one's gender randomly changes, and they often feel broken or fractured between multiple different genders.
For example, on one day, one might feel like they're 110% agender, but on the next they're "broken" into demigirl & nan0boy, androgynous, etc. Whether they feel like they switch between these genders throughout the time period, or feel like all at once, is up to the person.
History
Crystagender was coined by now deactivated tumblr blog blogging-n-stuff. The flag was designed and published by Pride-Flags on DeviantArt on July 4, 2015.