The Knights Templar
Founded in 1119, they hid in the shadows after 1307. They are based in London’s temple square, though their influence is global. They have built substantial financial, political, and social influence. They are assumed to be one of the largest secret societies in the world, with tens of thousands of members and a substantially larger group of unwitting associates.
Order of the White Crane
Founded in 900’s Japan by Abe no Seimei, who grew worried by the increasing Oni activity. With the blessing of the emperor, he gathered notable mystics, scholars, and warriors to defend Japan from supernatural threats. Though nearly destroyed in the aftermath of WWII, they have rebuilt over time, now choosing economic means to combat wealthy monsters, such as dragons and mummies.
The catholic church has known about monsters since its founding, and thus has a secret wing dedicated to fighting them. With the vast power of the church, they were instrumental in the defense of Europe in the dark ages. They are opposed to magic even today, and thus rely on other means to combat rouge magicians.
The Counsel of Venice