After a long time, Professor Elvin Gadd, also known as Professor E. Gadd tells the truth about what happened to Mario and Luigi's parents along with Sonic Sonia and Manic's parents. They were sent on a mission by Sentinel Prime to Yoshi Island, and they went missing. Now that they know the truth, they are willing to expose Sentinel Prime, but Sonic experiences a new change and a new form Dark Sonic