Infiltrate!
Shu finds the gang and and now is in the Grand Kingdom's capital city. While that, Grand Kingdom's army is fighting Jiburaro Kingdom's army. Shu Nand the others get inside Nene's place(nene is a villain). While Shu and the others are finding Nene, they discover that Nene is planning to take out children's shadows and using them as their weapons.
Aired 30/06/2007EP 13 - Infiltrate!
2007
Blue Dragon
As Shu's village was being attacked by an unknown enemy, he and his friends, Jiro and Kluke decide to defend their home. They soon meet warrior Zola and receive the powers of Shadow, an ability that let's them transform their shadow into a powerful monster. Shu receives one of the most powerful monsters, Blue Dragon, and they all set out to defeat their enemy.
(Source: Anime News Network)