In addition, [Duan Zhengming/Baoding] became a monk for a totally different reason [than the one in real-life]:
Chapter 10 (both 2nd and 3rd editions)
[At the Temple of the Celestial Dragon,] the Emperor Baoding said [to the Abbot Benyin]: "There are no words to describe my gratitude, Benevolent and Virtuous Abbot. But I wonder, is there even a little that I can contribute to the issue of dealing with the Enlightened Lord of the Great Wheel [大轮明王 Da4 Lun2 Ming2 Wang2]?"
"If we were to learn the Phenomenal Swords of Six Channels [六脉神剑 Liu4 Mai4 Shen2 Jian4] individually, none of us would succeed," said Kurong unexpectedly. "We just do not have sufficient internal strength to do it. But I have thought of a way that might do the trick. We will learn the sword of one channel each, but all six of us must exercise the technique together. Although it is better to refrain from violence than to fight six-to-one, we are not in this battle for individual supremacy in martial arts. Instead, we are doing this to protect our documents and temple. So, there is nothing anyone can say even if we send a hundred men out against him. The only problem is, we cannot find a sixth pugilist whose level of cultivation in finger-strength is equivalent to ours here in the Temple of the Celestial Dragon. Therefore, we have found it difficult to make a decision on this plan. Zhengming, you should just join in and make up the number. However, you would have to shave your head bald and dress like a monk for the plan to work." The pace of his speech increased as he spoke, as if he was feeling excited, but his tone remained icy-cold.
"It has always been my aspiration to have myself proclaimed as a Buddhist," said the Emperor Baoding, "but I have never heard of the profound mysteries of the Phenomenal Swords. Now that we are pressed for time, I am afraid..."
[The Abbot] Benyin spoke: "Zhengming, you are the King of Dali. Putting on a different set of clothes may be an expedient solution, but if the other party sees through the disguise, the mighty name of the Kingdom of Dali will certainly be damaged. There are both advantages and disadvantages to the plan, so I hope you will consider them before making a decision."
Putting his palms together, the Emperor Baoding replied: "I am duty-bound not to turn my back on protecting my beliefs and the temple."
"Very good," said Benyin. "However, since the Phenomenal Swords of Six Channels cannot be taught to secular disciples, you would have to take the tonsure before we can start training you. After our strong opponents have been beaten, you can resume your secular life."
The Emperor Baoding stood up and knelt with both his knees on the ground. "Please exercise your benevolence, Great Master," he said.
"Come over here," replied the Great Master Kurong. "I will give you the tonsure."
Source:
http://wuxiapedia.com/research/history/duan_family