[HeikaHaku]

Well, my friends at school were always coming up with nicknames for each other. When I complained to one of my friends (who didn't go to my school) that no one could come up with a nickname for me, she started calling me Haku. Well, Haku is taken in most places, so I add Heika. Heika is pretty much a word I just pulled out a dictionary, but there's more meaning to it, as well.

Heika means 'Emperor' in Japanese. I didn't choose it to call myself some high title, though. I liked how the word sounded, but also, it was because of a friend of mine who moved away a long time ago.
Her last name was Huang, which is Chinese for either Yellow or Emperor. (And some other, not as relevant things.) So, when I saw it, I thought it was perfect, and used it.

I've only been using Haku for less than a year, as opposed to my other name, though.

As for my older online name (which I've been using for about 6 years now), Omni-X, It was originally Omnimon, after my favorite Digimon. Then I saw the X-Evolution movie and added an -X. And since people called me Omni for short, it became Omni-X, or Omnix. In the event that those were taken, I'd sometimes use variations, like Omnis, or Omnisx.