- “You might be a Dao Sovereign, and you might be the First Patriarch of the Righteous Noble Sect, but your worldview doesn’t go past the Eighth Mountain and Sea!
I refuse to believe that with your cultivation base, you can’t see the righteous, noble aura on this apprentice of mine!„
- — Noble Ran to the First Patriarch in their argument regarding the presence of Meng Hao in their sect
on Chapter 1226: The Something-something Seal the Heavens Incantation
Noble Ran, whose real name is Xu Ran, is a character of major importance in I Shall Seal the Heavens. He taught the Seal the Heavens Incantation to Meng Hao, who later used it as the substructure of one of his most powerful divine abilities, the Seal the Heavens Hex.
With tens of epochs having passed since he was last seen, it is presumed that he is dead.
Meng Hao's second master and is a Patriarch of the Righteous Noble Sect. He has long been in search of a cultivator with a righteous, noble aura like that of Meng Hao's so as to pass on his most powerful and most mysterious Daoist magic, the "Seal the Heavens Incantation" he himself created.
Prior to Book 8
Not much is known about his history. He was said to have left the sect, but returned injured with his wife and children dead. He came back alone with only a piece of black leather in his hand before he lapsed into a coma. He occasionally becomes mentally disorganized from then on. No one knew as to what happened to his family since he never once talked about it. He can often be seen crying and laughing madly and oftentimes raving near the top of a statue in a mountain. 
After the incident which left him muddle-headed, he created the Seal the Heavens incantation. As to how he did it, it was never expounded.
He had a total of eight disciples before Meng Hao but sadly, all of them died in the midst of attempting to learn this daoist magic. One was struck by dozens of lightning bolts, another spontaneously exploded while cultivating, one caught fire and burned to death, and yet another experienced misfortune for two whole months before being crushed by a meteor. All his former apprentices died in strange ways, attesting to the difficulty of trying to learn this Daoist magic.
When he first saw Meng Hao, the latter was in the midst of taking the imperial exams in the Righteous Noble State as part of his disguise as a scholar. He immediately took a liking towards Meng Hao's "righteous, noble aura". When Meng Hao realized that his cover identity has been blown, he finished his exams all the while regretting not seeing the results come out and took off into the sky in an attempt to flee from Luo River. Midway through, he blocked Meng Hao's path and promptly offered the kid an invitation to join his sect.
As the cultivators from Luo River of came closing in, Meng Hao became unable to respond to his offer. But even before the cultivators could attack Meng Hao, he chastised them for trying to harm a fellow disciple of their sect. The local cultivators then replied stating that Meng Hao is a wanted man for exterminating the entire Blacksoul Society, but instead of getting dissuaded, he seemingly became even fonder of Meng Hao. Seeing their patriarch so determined, the cultivators hesitated on assaulting the so-called criminal. They were saved from their indecision when Lady Dragon-Snake, one of Chosen in the Nine Claws of Heavengod, appeared to detain Meng Hao. She, however, was unsuccessful.
Just as Meng Hao tried to attack a second assailant, he interfered to prevent the former from leaving Luo River. He then continued on in trying to get the kid to join his sect, promising him impressive gains should he accept. Meng Hao shook him off and turned away from the rather ridiculous invitation. But upon seeing the crowd of Dao Realm experts just beyond the planet, Meng Hao had no choice but to return to him and ask for his assistance. He then deterred all ten Dao Realm cultivators from the Heavengod Alliance from acting against Meng Hao.
After Meng Hao accepted his offer to be a disciple of his, he then made him learn the Seal the Heavens Incantation. Despite not wanting to learn the poppycock gestures and incantations involved in the technique, his disciple practiced the magical technique despite his initial misgivings. As Meng Hao hid away from the Heavengod Alliance, Noble Ran began his two month-long preparations to help out his apprentice in getting away. As they spent time training and meditating together, he eventually gained the respect of his own disciple. On the day of Meng Hao's getaway, he served as an interference to those who were after Meng Hao. On that day, he displayed the might of the incantation that they so mocked, receiving looks of awe and shock along with it. Even Meng Hao, who memorized the incantation was amazed and emotionally moved at the sight.
In the war between the Seventh Mountain and Sea and the Eighth Mountain and Sea as he was fighting against two Dao Realm experts, he kept trying to use the Seal the Heavens Incantation but to no avail since he used it to help Meng Hao escape. Because of that, he suffered the barrage of mockery of the other cultivators. When he was about to get killed, Meng Hao saved him and used the incantation to prove that his master is no fool, then he treated his injuries, gave him a jade slip to use it to borrow some of the power of the seal of the heavens incantation to teleport him to the Ninth Mountain and Sea and threatened anyone who dares to provoke him. That was the last time that somebody ever saw him. Even when the war with the 33 Heavens broke out, he couldn't be found. He may have altogether left the Mountain and Sea Realm even before then.