S4E11 J2, Rise of the Dragons

Uncle is searching for a large source of Dark Chi when the Chans encounter a mysterious girl in the junkyard. This woman reveals herself as Jade from the future, who has come back to stop the revival of Shendu by the hands of his son Drago, who has taken over in the future and now tries to secure a set of magic Dragon teeth hidden in the present to ensure his father’s resurrection. Jade causes Drago to destroy the teeth and thus prevent the spell from coming to pass.