To Help a Time Traveler

A few hours after Karl Jacobs' fight with Quackity, many of the DSMP Members are brought into a theater. Soon they are told that there is someone who Dream wants, even more so that Tommy, because this person was someone who was always foiled his plans in the shadows. They are promised not only answers of who this mysterious hero is, but why Dream is after them. Will them learning the truth finally change the course of history to prevent a disastrous future, or will Dream win?