She started life as your average shiny legendary being significantly more rare than the average members of her species. She'd be challenged by many fine trainers over the years, however they'd either run out of balls or she'd whipe their teams before she was caught leaving her free and wild. However one challenger did eventually best her and captured her, that trainer being a wolf named Cayden. As most trainers would do he soon set off to aquire a dna splicer for Ruby so he could eventually merge her with Kyurem, but being as special as she was she wouldn't settle for any 'ol splicer. She managed to convince Cayden to commission a more "volatile" splicer which would allow Ruby to merge with not only Kyurem as per usual, but also any other pokemon. The color layout of the splicer also being custom painted to match Ruby as well, the top spike simply being a custom shaved and shaped ruby followed by a layed of purple brushed metal to match the color of her tail as she powers up her flames (and her interal color as well, hehe), then a layer of black brushed metal to match her claws, white to match her fur, and finally a gold plated bottom tip to match her rings. She of course absolutely loved it and they were still amidst testing it to make sure it was totally safe when she simply just took it as all of the tests were done using her and her alone. So now she carries this custom dna splicer with her, stuffed in the floof of her tail to store it until she wishes to merge with someone or some other pokemon~

NSFW version: https://www.furaffinity.net/view/49937961/
NSFW intersex version: https://www.furaffinity.net/view/49938029/

Art by  astrodrak_adoptz