You're a pokemon trainer, and when you first got your starter, you picked a cute female fennekin you named Guenevere, or Gwen for short, she was a cheeky little thing, hungry thing too, she ate a lot and stole your snacks, but you couldn't get mad at her, but as she evolved into a braixen, her appetite got bigger, actually eating rattatas and small pokemon whole, this was worrying, but she always snuggled up with you, because she knew that calmed down your worries, but one day she might've made a mistake, while on the market on your city, exploring stalls that people set up, Gwen catched a glimpse of a basket filled with bunch of pokeballs, free for the taking it seemed, the owner of said pokeballs was arguing about selling those at a fair price or something, Gwen didn't hear that and gulped every pokeball down, and opened up, releasing every single, poison type pokemon in her stomach, in a panic you ran up to her and tried to force her to spit the pokemons out, since they were also poisoning her, but suprising everyone, she started leveling up as her stomach went overdrive, trying to digest its contents, letting out a loud belch in a purple cloud that wa also poisonous, she evolved, now, instead of evolving into a delphox, Gwen evolved into a weird variant, a new evolution never recorded before, fur with different purple tones, the stick turning into a bone, the fluff of her tail covering the sword blade, and most notably, her face, it now resembles a skull, four sharp fangs showing from her muzzle, which now resembles the upper jaw of a skull, her eyes are pitch black with orange glowing pupils, she seems confused, baffled, it was her dream to become a delphox and now, she's, this.