Complex sentence: Heart-broken, Yang Guo believed her and returned to the Condor who he had befriended earlier and continued his martial arts training, and develops a new palm technique called "Melancholic Palms," which responses to his disability and emotions.
Split into simpler sentences: Heart-broken, Yang Guo believed her and returned to join the Condor which he had befriended earlier and continued his martial arts training. He also developed a new palm technique called "Melancholic Palms," which responses to his disability and emotions.