I think I've shared this origin story somewhere before, but whatever...
Ironically I came up with this username on the SilentHillCommunity forum. It was a term I used to describe myself as someone whose mental wiring ended up faulty and abstract over the years, exacerbated by exposure to the less than savory parts of the internet and possibly undiagnosed aspergers. the word rodox sounded cool and had the connotations of something "messed up" or "not quite right". The underscore was added just as a throwback to older usernames, but thankfully I added it because I didn't think about the other meaning of the word "head" when I came up with it
It also became the name of a band I made up.