I mean, its a game with infinite magic I'm sure something could have been explained. For me what ruined it is her character changing. She went from a strong female character that actually had a personality and after she got hurt / the pirate arc she turned into some princess in a castle who couldnt do anything for herself and was just another body for MC to fix and fuck.Why didn't people like Eliza turning into a vampire? What alternative would be better for her to return to her movements? An Iron Man prosthetic?
Imo it would have been a way more compelling story to use her being human as a way to keep the MC grounded in his humanity while trying to grow in his powers rather than just give her a power up like its DBZ to keep her relevant.