this au is called WRAT.H AU cuz theres a (( fan-made )) substance called WRAT.H poison. this au is abt how eggman brings another egg((wo))man to defeat sonic once n for all. what eggman didnt know was that she was bad news. shed plan to take over eggmans empire in that dimension cuz she lost everything in hers. sonic underestimates her n loses his arm in their first fight. the weapon she used to attack n slice sonics arm off was covered in this so called "WRAT.H" poison. it spread profusely throughout sonics body, making different parts of his body a dark blue. when sonic uses too much energy, he coughs up a black liquid which glew blue in the light. this liquid was then sampled by tails to make painkillers n medicine to cure sonics condition. tails also made sonic a robotic arm. the new robotnik declared war which led to countless battles on mobius' surface.