Imperial Order of Ṣīyyōn
is the Order to Whom believes in the promissed land and the
celestial Jerusalem

This is one Order to Royal Knights that means Nobles, not common Knights, this Imperial Order grant a degree of nobility.

What is the difference between Zion and Jerusalem?
In the Old Testament, Zion is usually a synonym for the city of Jerusalem with its Temple Mount. New Testament prophecies predicted that the Lord would one day create new heavens and a new earth. As part of this new creation, a city of God called “New Jerusalem” would “come down from heaven from my God.”