Episode 1 to 10
The battle frontier opens, Diamond heads there, meeting Wally on the way. Battling Uranus in there too, becoming rivals soon. Wally finds out about the mining explosions happening there recently, and finds secret pokemon. Diamond challenges the battle castle and wins the tough facility, defeating Durach.
Episode 11 to 20
Dark Saturn plans to plunge the world into darkness, with no light. Pearl and Platinum enter a ancient town to learn about groudon and kyogre. Palmer captures regigigas, Diamond witnesses the event and is awed. He loses to Uranus badly in the battle tower challenge, who asks Saturn to teach him a lesson, Wally protects Diamond.
