Thrown in as a changling Queen far before the Canterlot invasion, and trust me mate, I got 99 problems and a Chrysalis ain't one.

Luna was never banished as Nightmare Moon. Instead someone else was and after a thousand years she had returned. Perhaps going to a costume convention was a bad idea.

Just a regular human turned into Nightmare Moon and visiting alternate Equestria. Totally normal.

What if in two hours you became queen of the windigos, have to save Nightmare moon, and right now all of Equstria fears you? Pff.. My life in a nutshell