Alas, the origin of my username isn't all that fantastic or fabulous. Originally, Usui Takumi was the username that I ripped from the anime/manga series Kaichou Wa Maid-sama!. It was 4 episodes in when I first started to watch Maid-sama alongside Durarara! (The correlation should be obvious by now). Unfortunately, that username was deleted from the current site due to various reasons involving bans and the lack of.
As time went on, a typo from a close friend of mine in chat somehow stuck and I have since been using the username Ucui as a main identifier.