Two years after the events of Power of Chaos, the two worlds have been living in peace. However, a certain event causes the two worlds to collide to each other. Now the heroes must collect the seven chaos emeralds in order to separate the worlds before it's too late. However... two new threats have appeared... A mastermind who's goal is to contain a powerful energy filled with darkness.... and a dark creature who appears in Sonic's nightmares. Will the heroes survive? Or will they perish...?

Evil is approaching earth and four special children were chosen to help protect it. Once the eggs hatch within them, join Haru, Tadase, Irou, and Amelia who will transform into "Ultra Sonic", "Chaos Shadow", "Powered Silver", and "Rebel Amy" as they put their skills to the test and fight the darkness that is a treat to earth. WARNING: back & forth transformations humans to hedgehogs.