Talk:Princess Luna/@comment-2012421-20170917022212/@comment-1276314-20170927182122

@CalimTheCrystalGem said it. I'll just word it differently: she was transformed and took all her magic with her, which also transformed to be compatible with her new evil self. Then the main cast purified her, thus losing pretty much all of her magic.

So yeah, logically she had to regenerate all of it and also heal herself if necessary.