Why is Su Xinghe called Mr. Cong Bian?

Su Xinghe, the head of Minstrel, known as Mr Cong Bian, is a big disciple of Wuyazi, the head of the school. A bard, mysterious and brilliant, has profound knowledge of martial arts and medicine. Apart from his martial arts background, Su Xinghe is very talented and proficient in piano, chess, calligraphy and painting, as well as medical divination. Those who have high demands on apprentices and don't accept stupid qualifications must be martial arts wizards, so there are few apprentices.