Well, mine is the alterego name of one of my characters, who I came here in part to play, so I decided yeah why not, let's just use that character name as my screenname. And the name itself, I was coming up with a showman-type or magician name, as that's what my character is, and he uses "special effects" a.k.a. "FX" in his performances, so I just wrote that out in a way that resembled a name.