If they don't, they are regarded as following the 'Old' version of the faith, which is considered a heresy. With Sons of Abraham, if a heresy becomes more prevalent than the parent religion (5 provinces more), it will become the new orthodoxy, and the parent religion will become a heresy. Orthodox Heresies can also mend the Great Schism if they manage to replace Orthodoxy as the parent religion. Restore Rome for real! With Holy Fury only Reformed Germanic, Reformed Tengri, and Reformed Aztec have the specified modifiers. Changing the religion of a character with character ID 4985 to Orthodox could be done with this command: For more CK2 commands, check out our Crusader Kings 2 commands list, and for more guides, check out our blog.
