Luna didn't turn into Nightmare Moon and wasn't banished to the moon. One day, at the school of gifted unicorns, Luna and Celestia sees the potential of Twilight Sparkle and Sunset Shimmer. Each of the princesses chooses one of them as a student. Twilight Sparkle and Sunset Shimmer will spend their lives as students with their mentors as they grow together.
Background belongs to Magister39
Princess Celestia vector belongs to DashieSparkle
Princess Luna vector belongs to DashieSparkle