Isn't that the monk who got kidnapped by vikings in Vikings?
I am unaware of the culture around non-binary people at the time and can't comment as to the popularity of their preferred naming conventions.
In Norwegian for example, "edel" and "adel" means noble - the former used for objects (a gemstone is an "edelstein" - noble stone; a noble gas is an "edelgass") while the latter refers to the nobility. You'll find one or both or variations in every (I think; certainly most) Germanic language.
We still have names derived from Æthel as well, e.g Ethel, Albert, Adele, Adolf, and others.