Ju Chang is one of the 7 Disciples of the Grand Master.
When Eun Aran wakes up at Hongmoon base and is interrogated. Ju Chang is pissed at Aran cause he feels he was entitled the 500 year old Ki. He decides to leave with his brothers and sisters to defend Tiger Sensei.
When they show up Tiger Sensei has already been defeated by Scorpion. He then challenges Scorpion but is defeated.
Then he appears underground in a room endlessly facing off against robots. Then a robot that has learned all his moves faces off against a already tired Ju Chang. Eventually he loses and becomes a mind controlled robot for scorpion.
He uses nunchucks to fight his opponents.