- “Sometimes when you find certain things with certain qualities, it’s just fate.„
- — Xu Qing on her first meeting with Meng Hao
on Chapter 1: Scholar Meng Hao
Xu Qing is one of the recurring characters in I Shall Seal the Heavens. She was the first cultivator to be introduced in the novel. As an Inner Sect disciple of Reliance Sect, she kidnapped four teenagers — Meng Hao, Li Fugui, Wang Youcai and Dong Hu — for the sect. Those four eventually became famous figures in their own right. She would later become Meng Hao's wife. She however, died on their wedding day.
She is described as being beautiful but cold. She is highly intelligent and a masterful strategist but naive in many matters beyond strategy.
She, like all the other disciples of Reliance Sect, was a mortal who was brought to the sect by force and thereupon became a cultivator. She is one of the only two Inner Sect disciples —the other being Chen Fan, and before Meng Hao claimed the third spot— and was thus respected. She would later be kidnapped by an elder of the Black Sieve Sect upon the Reliance Sect Sect Leader He Luohua's decision to disband the sect. 
An Inner Sect disciple of the Reliance Sect who was at the seventh level of Qi Condensation when she abducted Meng Hao, Li Fugui, Wang Youcai and Dong Hu in Mount Daqing because the sect required from its Inner disciples to bring humans from the mortal world in order to join the sect as servants. That was the usual way to join the sect, by force.
She gave Meng Hao access to her immortal gave after the latter decided to gave her a Dry Spirit Pill to get away from the pandemonium that was to follow after a distribution of the pill. The said pill is often fought over by the Outer Sect disciples after it is given to a cultivator that distinguished himself in one way or another.
Meng Hao, on a whim, also gave her a Cosmetic Cultivation Pill when she once chanced upon him in her immortal cave. This pill became of major importance to the latter parts of the story.
Later she, like other foremost disciples of the Reliance Sect, was forcibly recruited by a Nascent Soul expert from the Black Sieve Sect who took a liking to her cold vestige.
As a disciple of one of the Five Major Sects in Southern Domain, one would expect her to have had gained tremendous benefits. But contrary to expectations, she had to suffer being ostracized for refusing to be a concubine of Zhao Shanhe, a Conclave disciple of Black Sieve Sect. And so it came to a pass that the latter finally found an opportunity to capture and force himself on her. But she was later saved by Meng Hao who discovered her plight. After Meng Hao snapped off Zhao Shanhe's neck, he then tried to deal with Xue Yuncui who at that time was with Zhao Shanhe. As he moved to kill her, Xu Qing requested to that she be the one to deal with her, as Xue Yuncui was one of the several that made her stay in the sect more miserable than it should have been. She then took Meng Hao's sword and plunged it into Xue Yuncui's head, making it her very first kill.