In this chapter the Digidestined keep fighting old people. It's kinda the whole wise old master thing, with the elderly Babamon and Jijimon passing on their knowledge to the young heroes, and it does help, though obviously Tyranterramon doesn't die anytime soon, since the book isn't even half over yet. Still, even though the powers that the heroes obtain here don't win them the day, the lessons that they learn eventually contribute to the climax.
Oh, and fun fact, it is canon that Babamon is the elderly form of Rosemon, as mentioned below, but Oberomon is my own creation. Internets to whoever gets the reference.
Chapter Seven
Trial of the Forest