One of them is in the corebook, even! Jyudo Far-Flung rules a large territory that abuts a major Realm satrapy from his manse, in which he has amassed a great library. The Realm and the Sidereals 100% know he's there, they just can't get him out. They've tried. It didn't go so well.
Jyudo doesn't seem like he's all that interested in doing something like forging a daiklave, but I'd argue that a Lunar in his position absolutely has the time and resources to do so assuming their essence can be bent to that project with any facility at all.