The term "enbian" refers to an orientation in which somebody is a genderqueer person attracted to genderqueer people. In other words, genderqueer-loving-genderqueer.

It is the genderqueer version of a term like "achillean" or "sapphic" but not "veldian" or "lesbian". For that, you would use "cenelian".

Because identity and genderqueer identity in particular is complex and personal, genderqueer people basically always have grounds to call their attraction gay if they want to. However, some genderqueer people are specifically attracted to genderqueer people, and they want to use a term that refers to same-gender attraction but that is more specific than "gay" or "queer".

This also means that some relationships that some people might consider straight, genderqueer people might consider gay, e.g. demiboy4demigirl. With regards to these relationships, it's really up to the participants what kind of attraction they consider it. You can also have a relationship that is enbian and straight at the same time.

Enbian is different from "diamoric", in that enbian is gay-aligned in the way that a term like sapphic is gay-aligned. Meanwhile, "diamoric" refers to something other than straight or gay. However, one can be both diamoric and enbian, and one can even experience attraction to one person that is simultaneously enbian and diamoric.