This made by  Itoakami so after showing this that was being pass around https://www.deviantart.com/mainkore.....tage-844030715 we got into a talk and this what come out of it

It Serena as a rubber Braixen and her Braixen as a nice diaper in the world that they come form Team Flare made a gamma or solar ray that temporarily or permanently encases a trainer and even their pokemon as well in a rubber shell which absorbs their form(s) and reinverts them into a glossy rubbery shape of whatever suits the user Serena was unlucky to be facing them when they was testing it. Her and her Braixen got Capture and permanently become what they are now they soon found and rescued By Ember who was visiting their world at the time form team Flare after saving her she saw in this form she have powerful magic potential and take her back to her world to give her a new home and making her one of her first student she good at magic but at the same time mess up or falls behind in her study's with makes ember have to punish her for her own good but still fair to her letting her do things like fashion and Contests.

Serena is like any other Serena is most worlds but she is incredibly bashful, especially with her partner now permanently a wearable thanks to the Flare Ray effect and Braixen is isn't too pleased with her journey abruptly ending as a diaper but got use to it some what but still not pleased more so when Serena mess up and ember have to punish her she pays for it as well but is willing to boost serena magic and fire powers all and all they getting use to their new life thanks to Ember