Demiflux is a gender identity where one part is static, and the other(s) fluctuate(s) in intensity. For example, the static side could be female, but the other side could be male. The male part can fluctuate, going from full intensity (male), half intensity (demiboy), to no intensity (agender), while the female part does not fluctuate. It is similar to demigender in which the gender is almost “split in two” or divided into two sections. The difference is that demiflux has a part that fluctuates.
It could also be felt in a way that the intensity of their demigender identity fluctuates. For example, a female demiflux person (like demigirl) would feel demigirl most of the time but it could fluctuate between agender and full demigirl (and in between the two). There are many ways to define demiflux. It can be up to you.