Lion's Roar Lelouch x Reader

Back in the days when they were still living in Britannia, Lelouch and Nunally had a friend named (Y/N), a girl who was to grow up to be Lelouch's personally Knight and most valuable ally and a member of a family of Knights who had served the royal family for generations. Years later, Lelouch is shocked to find this phantom of his past has returned with a deep hatred for her home country and a drive to join the Black Knights. Exactly what had happened to her after his exile and could rekindled feeling from youth put both of them at risk?
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