I didn't make it with any particular meaning in mind. I just hate using generic fillers and diversifiers to make my names like xXx and 123 4141 ...etc I never have those in my usernames, so I always try to make my usernames using something that most people don't seem to use, that I think sound at lease somewhat cool. There are a million reasons why I could've included Delta in my usernames other than my reason, which was just because I thought the word was cool sounding. When I first used it, back when I was making a character in LaTale, I wasn't even familiar with the old greej alphabets or anything like that and if people asked me about it, I would respond with a confused look. As for the Edge part, I really dunno. I just knew that Delta would be taken, and wanted to add something on that sounded cool, and when i think of edge, I think of something like a razor edge, so I thought, hm, these might work well together.
tl;dr There's no actual intended significance behind my user name or any of them for that matter, I just thought it sounded cool. I guess it would technically be one of the edges of the delta symbol. Other past usernames that i've used include, but are not limited to: Zephel, ZioBolt, SwordDuster, ThetaFire, DeltaBolt, OkamiDeity(Had the game Okami on my mind at the time), TrinityEdge, InfernoOfIndigo,TrinityRazor, and the first username that I came up with myself, which was also my first email that I made without my parents back when I was 10 is MatoOrca(Don't ask me where I got the Mato part from, because I have no idea, and I don't think it's even a word, and I was thinking about .hack// at the time because I always liked .hack// even enough to watch those horrible rehashes of the same story with the same characters, just chibi-fied or genderswapped (i.e., .hack//Quantum

))And thus ends the not-so-brief history of my usernames from 2004-present.