If Sonic characters were infected by Baby from Dragon Ball GT, they would likely be taken over by his mind control and become evil versions of themselves. Sonic would become a ruthless and power-hungry dictator, Tails would be a twisted and manipulative genius, Knuckles would be a fierce and merciless warrior, and Amy would be a cold and calculating femme fatale. The infected characters would stop at nothing to achieve their goals and would pose a serious threat to the rest of the world. It would take a lot of effort and teamwork to break free from Baby's control and return to their normal selves.