The Return of the Night Master

"The Return of the Night Master" is Episode 10 of Yin Yang Yo!

Synopsis
Many years ago, Yo was the only Woo Foo warrior who was left during the battle against the world's greatest evil, the Night Master. Yo used Woo Foo to defeat his enemy, but because of the Amnisulet, everyone forgot that Woo Foo saved the world. Now people make light of Woo Foo warriors. The Night Master plans to free his army from the spell Yo put them under during a dodgeball tournament in the park. Yin and Yang see the tournament and ask Yo if they can join. Yo says no, adding that true martial artists don't use their skills in ways that bring up mad emotions. They enter the tournament anyway and get beaten by everyone they go up against. The Night Master appears in the shadows and offers them special training to use their Woo Foo skills with mad emotions. With Yin and Yang using mad emotions, the spell is broken for the Night Master's army.