El o El, no but who was the third horde guild to leave?
Ropetown transferred due to server performance issues.
Apocalypse did as well, but their encounters weren't quite as latency sensitive.
Turmoil left, but I don't think anyone really cared.
im pretty sure apoc and rope are the only top guilds that left for the most part for another server. The other ones just fell apart and then the old school guild like KOTS/ PD remained.