DPA018: Team Galactic's Ultimate Warrior

Team Galactic's Ultimate Warrior (ギンガ団最強の戦士) is the 3rd chapter of Volume 4 of the Pokémon Diamond and Pearl Adventure! manga.

Synopsis
Cyrus captures the last Lake Guardian and Hareta and the Gym Leaders are in front of Team Galactic headquarters. They enter the headquarters but the Gym Leaders begin to disappear one for one until Hareta and Byron are left. The two of them enter a big room and they have to face Mitsumi, Team Galactic's ultimate warrior.