ahhh that's a good idea kill the leader of a high powered guild, make sure another high powered guild gets the blame while making sure the new leader is completely under your control.. (charmed, dominated, or just a loyal follower of the cult). Then use these newfound connections to start effecting legitimate guilds with blackmail or other underhanded means. The beholder could then have sufficiently cowed (sp?) legitimate people introduce new members (sufficiently loyal of course) into the guild or eventually the governing body.
ah yes this will be a very interesting campaign
ah yes this will be a very interesting campaign