The plot mainly focuses on the return of the Joker in the Batman Beyond universe. He creates chaos and challenges the new Batman. There are intense battles and a lot of mind - games involved as the new Batman tries to stop the Joker's evil plans.
The two main characters are Terry McGinnis, the Batman of the future, and the Joker. Terry is a young man with his own set of skills and challenges. He has to uphold the legacy of Batman while dealing with the present - day threats in his city. The Joker, on the other hand, is the iconic villain, full of madness and chaos. His return shakes up the status quo in the Batman Beyond world. There are also other supporting characters like Bruce Wayne, who serves as a mentor to Terry and has his own history with the Joker.