Bregan D'Aerthe is the dark elf clan of Drizzt or some shit from a very popular Dungeons and Dragons world book series. Guilds named Bregan D'Aerthe have probably popped up as many times as characters named "Xsephirrothx."
I was one of the original members of Bregan on this server. The founder was literally an extremely annoying 15 year old halfling druid that tried to get a bunch of lvl 20-40s to raid Runnyeye and iirc he was lvl 35 for fucking ever. There was a half-elf paladin and a wizard (sanluen, I believe) I was friends with and we'd would make fun of him all the time, but he would just take it since we were 40+ which was high at the time. The paladin and I came close to quitting together, I did and he ended up saying he'd stick it out for a little longer. I took a year or so off P99 and came back to see he was leader and fucking decked out, I don't remember his name, but I think it vaguely sounded like Sanluen coincidentally.