Hmm… it looks to me like it is the
Unicode “High Voltage” lightning bolt character, U+26A1? I went to edit-artist, and tried to add a koppa, and there was a distinct difference between the koppa and the character already in the name. And when I copied the lightning bolt glyph from the unicode page into the edit-artist page, it looked the same.
(I’m not arguing that it should stay the lightning bolt, just asking if it is)
let’s see what they look like in the forum-- koppa: ϟ(ϟ) lightning bolt : 
(⚡)