Fessigender

Fessigender is a subset of genderflux where someone has a gender (usually 100%, rarely floating between 100%-80%) but they become agender/genderless and/or float between 10%-0% of gender while being physically tired (exclusively or not).

One may (but don't have to) be slowly getting from 100%-80% to 10%-0% of one's gender while getting more and more tired.

Subsets
Fessiboy - someone who's "default" gender is Male

Fessigirl - someone who's "default" gender is Female

Fessinonbinary (fessienby) - someone who's "default" gender is Non-Binary

Entymology
the prefix fessi- comes from the latin word meaning "tired"