Books like the pendragon adventure

The Pendragon Adventure is a young adult series of ten science fiction/fantasy novels by D. J. MacHale published from 2002-2009. The series made the New York Times #10 Best Seller list and has sold over a million copies.

They follow the chronicles of Bobby Pendragon, an American teenager who discovers that he, as well as his two best friends, Mark Dimond and Courtney Chetwynde, must prevent the destruction of the ten "territories": distinct but interrelated space-time realities. Each book deals with the battle over a particular territory, fought between Bobby's side—including the lead protectors of each territory, called Travelers—and the forces of Saint Dane, a demon who exploits a decisive "turning point" in each territory's history. At this turning point, Saint Dane steps in to guide each territory towards utter destruction; it is up to Bobby Pendragon and his allies to stop or reverse Saint Dane's sinister efforts.