Sorry to rain on the parade, but it's not Plaz/Sephiroth. It's well established that Plaz and Sephiroth are the same person.
Plaz/Sephiroth's real name is Alex Roncelli. He establishes that on the forums here:
Plaz (alex roncelli) is the same person as sephiroth. It was a dual act I pulled off.
I have been facebook friends with Alex Roncelli (Alex Celli on Facebook) for years. I have known always known Plaz under that name. He's a gigantic troll, a staunch republican, and pretty wacko, but he's not a killer. He posted 12 hours ago, after the shooting happened, on facebook: