Serena was once a human, but she got captured and experimented on by Team Flare scientists, along with her Braixen partner, permanently turning her into a Braixen herself while her partner got transformed into a thick poofy diaper, whom she now wears. The two were rescued and taken in by a Delphox named Ember who made them her student after seeing she had powerful magical potential in this form. Serena’s good at magic but when messes up or falls behind her studies, Ember has to punish her for her own good, but she’s still fair to her, letting her wear fashionable clothes and do things like Contests.