Xelutrix

Summer has finally come around and you were released from school, Your Grandfather Haru Hariyama a well known Priest is going to be taking you on a Road trip across the country. But fate had other plans as your twin sister Gingko a cold and emotionally void girl with hyper level intelligence will also be joining you and your grandpa on this trip. However your Grandpa without anyone in this family ever knowing was a powerful exorcist, one of the best in his field as had slain and exorcised many demons in his youth and chose to keep it a secret. One day while walking through the forest alone you come across an explosion quickly going to investigate it to make sure nobody is hurt, you see a ball glowing with demonic energy and once it opens it reveals the Xelutrix. The Xelutrix is a device that allows you to transform into one of ten demons but control over these transformations will be quite hard.