Basically, Evna comes from "evne", meaning "ability", which I often paired with other words to make usernames in MMOs back when I was trying (and failing) to learn Norwegian.
The "evn
a" spelling came later when I converted the word to a fictional language I was developing, but according to Google Translate, "evna" already means "their ability", but I dunno if I should trust that. But it still works if it's true.
The "mishko" comes from the word "mishkoswIn", which means "strength" in the Potawatomi language.
My school was built in honor of a Potawatomi historical figure, and after seeing the word on a poster, I decided to adopt it as the name of a character in a fantasy story I was working on at the time, whose culture was inspired by Native American cultures.
I decided to use the name for myself as well, add on the "Evna-", and we get Evnamishko. It has the rough meaning of "ability and strength," and is a self-encouraging name. Plus I like the sound of it.