The Order of the who? Of the What?
If one travels, you might notice it. Each one has a blue orb on their signage or somewhere in the shop. The merchants seem to specialize in foreign goods, but often buy local produce and products, to trade in other places. They seem totally unrelated to the others. It seems to be a secret organization, but nobody knows for sure.
The Blades of the Golden Sun are an organization lost to history. They are a legendary group, with songs, stories, and histories written about the exploits of their members. They were warriors of the famous Sun Swords, fighting against “The Evil”, the Dark Night.
A great listing of names and short descriptions as well as fleshed out groups/ societies/ and organizations.
A secret MLM (pyramid) company that offers eternal life, but in fact it transfers the life forces of its members to those position "above". If you get high enough, (meaning you get enough new members) you start to enjoy the benefits. Maybe a willing sacrifice is much more effective for the transfer. But no one says, that a suddenly unwilling member, threatening to tell the authorities, may not loose it involuntarily... thus start people to vanish, and aged corpses are deposited somewhere safe.