Seriously, are you so devoid of creative thinking that you can't think up a name for yourself without resorting to copying a well-established one? What is it that drives you, are you hoping that Sephiroth's "coolness" will rub off on you? Are you so oblivious to the fact that when other people see you they're usually think "Geez, here comes another moron"?
The reason for this little outburst is not purely ideological (we've had "Sephiroths" around since the old days), but more of a practical one. At this moment, we have 22 people using a simple variation of the name "Sephiroth" as their user name (and probably a few more using a bad spelling). It's not only uninnovative, it's downright confusing. So the following people should strongly consider changing their user name to something we can actually recognize you by, before the management decides to do some culling of the herd:
Sephiroth the Dragon
The Great Sephiroth
TheGreatSephiroth (oh for f*ck's sake...)
On a similar note, there are also 20 Clouds, six Squalls and three Zacks. If either of you want to have an actual identity, you might consider the same.