It's something I randomly came up with though not specifically for this site it's for anything where I don't particularly want it linked to my usual stuff.
My name is from the time when I had no specific fetishes or preferences for hentai other than happy sex between a guy and a girl. Vanilla content. Thus, a vanilla fetish.
The logic behind mine is kinda senseless. It's meant to be a mix of an old nickname I used to go by that was quite generic and a dumb joke from Shuffle! a friend started using as a semi-nickname for me. Due to my old nickname being generic I came up with desufin instead from the Shuffle! joke mixed with my old one (and part of the boatlights-chan spam from old /b/ days because why not).
I mispelled Redler many, many years ago. A Redler is a Zoid from Zoids: Chaotic Century, and I thought it was kick-ass back then. I've since moved on to the Gordos.