The Seventh One Awakens

The Seventh One Awakens (吠えよ獣王拳, Shichininme no Kakusei) is the twentieth episode of Digimon Adventure:

Summary
Yamato’s younger brother, Takeru, is unexpectedly found in the Digital World, held captive by a powerful Digimon. With the help of Leomon’s army, Taichi and Yamato attempt to save Takeru.