- “You have your glory, and I have my pride!„
- — Chu Yuyan to herself after Meng Hao's visit to Violet Fate Sect
on Chapter 760: Your Mother Was Here
Chu Yuyan is a recurring character in the novel I Shall Seal the Heavens.
She is one of the major figures in the series who was first introduced as a Chosen from Violet Fate Sect and the fiancee of Wang Tengfei. She went along with a few elders from Wang Clan to fetched Tengfei from Reliance Sect after the latter decided to desert the sect. They would later call off their engagement due to circumstances that predominantly involved her and Meng Hao.
Incredibly beautiful, tall and slender. She wears no makeup but her bare face glows like the coming of dawn. Her hair is tied up in the style of a swallow's tail and has jade-like skin. She emanates a magical aura that is composed, cool, and refined all at the same time. She is often described as looking like a celestial being who descended from the heavens.
She is the daughter of a Sect Leader of Violet Fate Sect. She is also known all throughout Southern Domain as one of the Four Great Beauties. She is an alchemist and a member of Violet Fate, a core disciple within its' East Pill Division.
Chu Yuyan was introduced as the beautiful fiancee of Wang Tengfei. Through a series of events, she ended up being captured by Meng Hao and forced to concoct the Perfect Foundation Pill. During that time, she also gave him an advice which helped him during the Blood Immortal Legacy tournament. Later, she was seen in Meng Hao’s presence, wearing his clothes. This led to rumors — primarily propagated by Li Fugui— that she was having an illicit affair behind Wang Tengfei’s back. Angered, Wang Tengfei participated in the Song Clan's search for a son-in-law, after which Chu Yuyan returned the engagement agreement to the Wang Clan, thus ending their relationship.
Later, Meng Hao joined the Violet Fate Sect under the Fang Mu persona. Chu Yuyan immediately disliked Fang Mu, and repeatedly attempted to find out why. Later, she developed a fascination with Grandmaster Pill Cauldron, who was of course Fang Mu/Meng Hao.
In the Violet Furnace Lord trial by fire, she finished third overall after Fang Mu and Ye Feimu, but was nonetheless permitted to become a Violet Furnace Lord. After learning that Fang Mu was, in fact, Grandmaster Pill Cauldron and not Ye Feimu, she had extremely complex emotions regarding him.
In the mental realm of the Choumen Tai's corpse, she and other Violet Fate Sect disciples were saved by Meng Hao/Fang Mu. Shortly thereafter, she learns that Fang Mu and Meng Hao are one-and-the-same, and is left with complex emotions.
After the Frigid Snow Clan moved to the Violet Fate Sect, Hanxue Shan learned from Chu Yuyan that Meng Hao is in fact Grandmaster Pill Cauldron. On the surface, Chu Yuyan hated Meng Hao, but deep inside her heart she longed for him.
During the Ancient Dao Lakes erruption, Chu Yuyan asked Meng Hao if "there can someone other than Xu Qing", to which Meng Hao responded, "the opportunity was there, and now it's gone". Heartbroken, Chu Yuyan left.
After hearing of Meng Hao and Xu Qing's wedding, Chu Yuyan was extremely sad. When Xu Qing and Meng Hao came to the Violet Fate Sect to get Grandmaster Pill Demon's blessings, Chu Yuyan repeatedly avoided Meng Hao.
When Meng Hao visited the Violet Fate Sect after winning the Southern Domain Civil War, he looked for Chu Yuyan but couldn't find her. When he was leaving, Chu Yuyan murmured "You have your glory, and I have my pride".
Soon after Meng Hao entered Nine Seas God World, the Demonic cultivators kidnapped Chu Yuyan and poisoned her, in an attempt to get back at Meng Hao. Enraged, he went to Seajacket Island and slaughtered eight of the nine members of the Divine Sea Realm and two elders of the Demonic cultivators' faction.
After returning to the Sect, Meng Hao slayed any and every Demonic cultivator that he saw, regardless of whether they hindered him or not. After alleviating Chu Yuyan's poison by using the heart blood of ten Sea Dragon Demonic cultivators, Meng Hao brought her with him to the Windswept Realm.
When they were about to depart from the Windswept Realm due to latter's uprising, in an attempt to help Meng Hao, she tried to ascend to the Immortal Realm and was grievously injured in the process. She however, had her own soul damaged making it vulnerable and ended up having part of her soul trapped by the Blacksoul Society.
It was stated that she was unwilling to enter the cycle of reincarnation solely because of her love for Meng Hao. He searched for her reincarnation but discovered that she does not have one. It was then revealed by Xu Qing that Chu Yuyan would rather live in a world of her own creation than to reincarnate again forever pining for Meng Hao. Xu Qing then added that should Chu Yuyan ever decides to wake up, the three of them should practice cultivation together.
She later disappeared from the coffin she was laid in and her current whereabouts are unknown. It was however, stated by Meng Hao that she was taken by a powerful person with a cultivation base no lesser than his. He took it as a sign that Chu Yuyan is in no danger, and it can only be considered to be a great fortune for her. 
She was revealed to have been taken in by Old Man Extermination as his disciple. She remembered all the things that happened in all her past lives and because of her master, she eventually chose to stop trying to forget. She and Meng Hao met again countless epochs later.
Second Life (see Yan'er)
The rest of her soul was captured by Han Bei, who used this as a leverage against Meng Hao. As Han Bei used her own life force to sustain her soul to keep it from dispersing, they then became symbiotically linked to each other. It was revealed that it can only be separated by one who had transcended.
She was sent to one of the mortal villages in Planet Vast Expanse to be reincarnated as Yan'er (her current name). When she grew up, Fang Mu (Meng Hao's clone), took her in as his disciple. She retained her interest in alchemy with Fang Mu occasionally guiding her with regards to cultivation.
She is described as beautiful, social and easily makes friends. Tomboyish and seemingly has none of the grace that most females possess. She is headstrong and willful which often frustrates Meng Hao, or in this case, his clone. She often attract attentions from both genders (mostly from the males) that inadvertently leads her to trouble. Her beauty induces some to lust after her (as seen when a sect prince from the Eighth Sect kidnapped her).
- The Chu in her name is a family name. Yu means “jade” or “beauty,” and Yan means “captivating”. (Source: Wuxiaworld)
- Meng Hao used Lord Fifth and the nine shards from the Copper Mirror to separate Han Bei's soul from Chu Yuyan's.
- Even though many epochs passed between Chu Yuyan accepting Extermination's proposal to be his apprentice, and when she saw Meng Hao again at the end of the series. For her it was only a few months or years at most since a epoch for Meng Hao at the time was only one month for Chu Yuyan.