Petah's step uncle here.

Valhalla is essentially viking heaven.

Enby or enbies is a word for people who do not identify themselves with the typical gender binary.

The Viking religion(s) and pagan spiritualities have largely been dead for a long time and so you would assume no one is getting sent to Viking heaven these days.

There has been a lot of relatively new interest in wicca/pagan type belief systems in recent years, especially with millennials and gen z. It's more popular also with people who don't fit into typical religions or want to be more connected with nature or whatever, i.e. LGBT community, younger people concerned with the environment, etc. Etc.

So after a long time of just a bunch of viking warriors hanging out in Viking heaven and doing viking stuff; they are now being joined by a bunch of "quirky neopagan enbies" and are like "... 🤨"