DPA023: The Advent of the Legendary Pokémon!!

The Advent of the Legendary Pokémon!! (伝説のポケモン降臨!!) is the 3rd chapter of Volume 5 of the Pokémon Diamond and Pearl Adventure! manga.

Synopsis
Hareta and Jun or on their way to Mt. Coronet while Mitsumi and the others stay behind to prepare themselves for the battle. On Mt. Coronet they meet Jupiter and Mars and Jun battles Jupiter while Hareta battles Mars. Cyrus however has awaken Dialga and is ready to destroy the world.