Xie Yu was called the Marquis of Ningguo because he had married Princess Liyang, the younger sister of the Emperor of Daliang Kingdom. He had also performed well in the Red Flame Army and gradually gained the Emperor's recognition and reward. Although he was the consort of the Grand Princess of Liyang, he was given the title of Marquis of Ningguo because of his outstanding military achievements. On the door of his mansion, there was even a pillar inscribed by the Emperor of Daliang to protect the country, which showed how much the Emperor valued him.

Xie Yu, the Marquis of Ningguo, fell in the 51st episode of Nirvana in Fire.
Xie Yu, the Marquis of Ningguo, ended up being stoned to death during his exile.
The Marquis of Ningguo and the Duke of Qingguo were both titles of nobility in ancient China. Duke Qingguo was a first-class duke. There were nine people who could be tested in each dynasty, including Song Renzong, Wu Qian, Xia Song, etc. The Marquis of Ningguo was a type of marquis and represented the status of a marquis. According to the search results, it was impossible to determine which position was higher, the Marquis of Ningguo or the Duke of Qingguo.
Jia Yu was the main character of a time-travel novel. In this story, Jia Yu became the adopted son of Jia Jing of the Ningguo Manor, but he was not valued. However, he had awakened a check-in lottery system, and on his first check-in, he had obtained the Iron Letter Certificate, which was known as the Immortal Gold Medal. Jia Yu used this system to start interfering with the affairs of the Ningguo Manor, successfully stopping Yuan Chun from entering the palace, and played an important role in the Jia Manor. This story described Jia Yu's rise in the Ningguo Manor and his influence on the affairs of the Jia Manor.
There was no clear answer to Marquis Yan and Xie Yu's official positions. Although Xie Yu held a higher position, Marquis Yan possessed great influence and resourcefulness in the court. Thus, in terms of power and influence, Marquis Yan was superior. However, the specific ranks of official positions were not mentioned, so it was impossible to determine the rank of Marquis Yan and Xie Yu.
Xie Yu was a Marquis with real power, while Marquis Yan was an idle noble. Although Xie Yu held a higher official position, he was very wary of Marquis Yan. It was clear that Marquis Yan possessed great influence and resourcefulness in the court. Thus, it could be said that Marquis Yan was superior in terms of power and influence.
Xie Yu's official position was even higher. Although Marquis Yan had great influence and resourcefulness in the court, Xie Yu was a first-grade military marquis and had the trust of the Emperor. She was in charge of the patrol camp and was also the trusted aide of the Crown Prince. Thus, Xie Yu's official position was even higher.
Marquis Yan barged into the Xie Manor in the twenty-first episode of the television drama " Nirvana in Fire ". In this episode, at Xiao Jingrui's birthday party, everyone planned to take down Xie Yu. Marquis Yan went to the Xie Mansion in time and stood on the steps. Although there were people blocking him, he steadily moved forward, showing a strong aura. He didn't say a word, but he was stronger than thousands of soldiers and horses, forcing Xie Yu to retreat. This scene was very exciting and left a deep impression on the audience.