From publisher blurb:
Enter a bold (and tiny!) new region of Théah! Here you will find the history of a small nation surrounded by larger cultures and trying to maintain its unique footing in the world. Inspired by real world micro-states like Luxembourg and Lichtenstein, Lustain is a small neutral state nestled between Eisen and Montaigne. Protected and bound by the powerful oath magic known as Eid, Lustain is a place where you can trust everyone completely... Until you can't. Intrigue abounds as the brilliant and legalistic Eidhoren mages are hired out by other nations and companies to enforce treaties and contracts.
Included are history and culture, a new dueling style, new backgrounds and advantages, and a new style of sorcery with immense storytelling applications.