Lucy staying the same (or trying to at least) because she fears that if she changes koia won't recognise or believe her, only for when they reunite for KOIA TO BE AFRAID THAT LUCY WONT LIKE HER BECAUSE SHES CHANGED SO MUCH!
Which to Lucy feels like a slap in the face, and basically, lovingly, tells her off for, how she'll always love her over & over again, she doesn't care! Lucy's changed too! She's changed so much! It's not until then that she actually shows how much she's changed. She's angry, scared, guarded, all because of this stupid curse.
Yes she's the Sunshine character, but she is so, so much more than that. She's a scared, guarded, angry kid, because how can she not be? Zyrane has physically abused her for so long, making her feel like all her imperfections are awful and that koia would never love her again if she showed how angry she truly was.
How she lashes out at people for no reason. Lucy's a parallel of elley, and that's why they became friends. Lucy saw herself in her and wanted to help her, to make her different from herself.
She's angry.... she's just really good at hiding it.
