The Blackest Blade
The Assassin Guild is not an official guild in Sai-Inur.
The Assassin Guild hires out its members to do jobs that relate to killing or finding individuals. Contacting the guild is difficult, but they are good about contacting someone who is interested in them.
The Guild has a leader, but nobody knows who, or what, it is. The rumors range from some drunk geezer to a god to the Council itself.