Luna was coaxed into therapy following her initial retirement, only to realize Nightmare Moon still existed, now almost totally independent as a personality. After a LOT of difficulty, Luna, Celestia & Nightmare Moon came to an understanding, and the newly-dubbed “Nocturne” was given a measure of freedom. She was allowed to manifest separately from Luna, with more energy needed to have more of a physical presence or be further from her mind-sister. While “reformed” and no longer purely a villainess, Nocturne is still morally grey, and tends to be more ruthless, aggressive and direct than Luna.