Duan is fictionalised as a character in the wuxia novel The Legend of the Condor Heroes and its sequel, The Return of the Condor Heroes, by Jin Yong. He is depicted as a formidable martial artist and one of the Five Greats, the five most powerful fighters in the jianghu (martial artists' community), alongside Wang Chongyang, Huang Yaoshi, Ouyang Feng and Hong Qigong. In the first novel, he emerges as one of the top five champions at the first martial arts contest on Mount Hua and earns himself the nickname "Southern Emperor". He is famous for his signature martial arts technique, the 'Yiyang Finger'.
In his early life as the emperor of Dali, Duan was extremely obsessed with martial arts and neglected his concubine, Liu Ying. Liu Ying had an illicit affair with Zhou Botong and bore him a son. However, the infant was critically wounded by a masked attacker (later revealed to be Qiu Qianren). Liu Ying pleaded with Duan to save her child's life but he refused and the infant died. She swore vengeance on him and left to lead a reclusive life in the Black Swamp. Duan felt remorseful later so he abdicated and became a Buddhist monk known as "Reverend Yideng". His top four aides – Chu Dongshan, Zhang Shaoshou, Wu Santong and Zhu Ziliu – follow him to practise Buddhism and disguise themselves as a fisherman, a woodcutter, a farmer and a scholar respectively .
Guo Jing brings Huang Rong to Dali to seek help after the latter was wounded by Qiu Qianren. They encounter Liu Ying (renamed to Yinggu), who directs them to Yideng. Yideng uses his immense inner energy and the 'Yiyang Finger' to heal Huang Rong at the expense of his life. Shortly after, Yinggu appears to kill Yideng because she knows that he is now weakened and deprived of energy, but Guo Jing and Huang Rong intervene and stop her. Yideng recovers after Guo Jing imparts the Nine Yin Manual skills to him. Yideng appears in the final chapters during the second martial arts contest on Mount Hua. Qiu Qianren shows up and falls off a cliff after losing his footing but Yideng saves him. Qiu Qianren feels ashamed of his past misdeeds and grateful to Yideng for saving his life, so he agrees to become a Buddhist monk to atone for his sins and becomes Yideng's apprentice.
By then, Dali has been conquered by the Mongols, who are forming a two-pronged attack on the Song Empire from the north and south. Yideng participates in the Battle of Xiangyang and helps the people of Song fight the Mongol invaders. Yideng also appears at Passionless Valley, where he helps Yang Guo and Xiaolongnü deal with Gongsun Zhi and Qiu Qianchi.
Yiyang Finger is is Yideng's signature martial arts technique. The skill allows him to channel inner energy into his fingers and propel towards enemies and deal a great amount of damage. He also uses this technique to save the lives of people who have been poisoned or have sustained internal injuries, by using his inner energy to purge venom from their bodies or clearing their meridians to improve blood and energy circulation.
First Heaven SkillEdit
First Heaven Skill is Yideng's inner energy cultivation technique. He learnt it from Wang Chongyang in exchange for teaching Wang his 'Yiyang Finger'.