>Charlotte's super bitch half sister
I know it's fanfic tier but I kind of want that. Charlotte has a half sister that resents her for what she did to her mother and actually having her father's favoritism for being picked French rep that she enrolls at IS academy to beat her.
Not that I have touched Utena, but I'm planning on giving Charlotte a half-brother for my fanfic Senjou no Kodoku na Shounen (https://www.fanfiction.net/s/9234446/2/Senjou-no-Kodoku-na-Shounen).
Making a prolific mother out of the German girl.