So, while thinking of a slightly more original way to mix usernames, I got to thinking what different words could be made from my username. After about 10 minutes of failing to come up with anything decent, I decided to search for a site that would do it for me, here are some of the results.
A couple of the sites I used:
Anagramsite.com - A List of Anagrams
Internet Anagram Server
If your username is too short, try your favourite anime.