Liu Yu is a disciple of Han Li from the Heavenly South Region. She was originally raised as one of several candidates to fuse with a Wood-attributed Spirit Nascent cultivated by the Spirit Controlling Sect that would've allowed her to reach the Nascent Soul stage. Fate would instead result in her becoming a disciple of Han Li, and the Spirit Nascent becoming his second Nascent Soul.
As a Spirit Nascent fusion candidate, Liu Yu along with Han Yunzhi (another candidate) was sent to search and retrieve a missing Wood-attributed Spirit Nascent. Her search would take the pair to the State of Yue where it had gone missing. As a result of their search, Liu Yu met an Early-Nascent Soul stage Han Li as he detected her lingering spiritual sense that allowed her to locate the Spirit Nascent.
After noticing that she had been detected, she along with Han Yunzhi fled towards a group of Ghost Spirit Sect cultivators. After a brief exchange, the group detected the hostile spiritual sense of a Nascent Soul (Han Li) cultivator. Liu Yu used the chaos of the fleeing group to make her own escape by fleeing in a different direction. Unfortunately, she could not outrun Han Li using his Thunderstorm Wings.
When Han Li caught up to her, she released her Six-Winged Frost Centipedes in an attempt to slow Han Li by freezing him using Icy-Qi. However, she was surprised when Han Li effortlessly shrugged off the attack by absorbing the Qi. Luckily for her, possessing the Six-Winged Frost Centipedes resulted in Han Li's choice to abduct her rather than kill her. She was rendered unconscious and taken back to the Drifting Cloud Sect.
When Liu Yu awoke in the Drifting Cloud Sect, she formally met Han Li and was surprised by his youthful appearance. She revealed the secrets of the Spirit Nascent upon questioning by Han Li knowing that her life was in jeopardy if she were to withold information. During her discussion she came to learn that Han Li wanted her Six-Winged Frost Centipedes to accelerate refining his Celestial Ice Flames. Liu Yu realized that the Spirit Controlling Sect would kill her if she were to return or become a vagrant cultivator. She sought protection by becoming Han Li's disciple in exchange for her Six-Winged Frost Centipedes. To agree to the deal, she accepted a soul restriction placed on her by Han Li. Once the restriction was in place she officially became his disciple and officially entered the Drifting Cloud Sect under a different name.
Abduction in the Devilfall Valley
More than 100 years later, in order to break through her cultivation bottleneck, Liu Yu along with Song Yu and Mu Peiling traveled to the Devilfall Valley to obtain an Illusionary Spirit Herb to refine an Illusionary Destruction Pill to assist all 3 in breaking through their cultivation bottlenecks. Thanks to the Elder Devil Bloodflame leaving the Devilfall Valley, the restrictions on the outskirts of the valley weaken every year making it safe for Liu Yu to forage for materials. However, she didn't find the herb in the outer valley and was forced to search the inner valley which still had dangerous spacial tears. Initially she was reluctant to take the trip until Song Yu persuaded the group using Fairy Violet Spirit's map of the valley from the incident that released an Elder Devil in the Heavenly South, years earlier.
Unfortunately, while foraging the inner valley, Liu Yu encountered Han Li's second Nascent Soul that gained sentience in the 80 years that it had been separated from Han Li. She along with Song Yu and Mu Peiling were abducted and detained by this rebellious second Nascent Soul using an illusion formation in a cave deep underground a sea of lava. Using the original Han Li's experiences, the rebelling Nascent Soul built and hid the trio using methods that it thought Han Li could not break.
When the second Nascent Soul was in the Myriad Depth Devilish Abyss fusing devilish Qi into his body, much to her surprise, Liu Yu was found and rescued by Han Li who she hadn't seen for nearly a century. She was surprised to learn that he had progressed to the Late-Nascent Soul stage becoming one of the Heavenly South Region's great cultivators. Now freed, she returned to the Drifting Cloud Sect along with Song Yu and Mu Peiling.
Later, upon Han Li's return to the sect, all three of them was given a bottle of Illusionary Destruction Pills. Additionally, since her master wanted to go into secluded cultivation, she agreed to take on his responsibilities in overseeing the sect in exchange for secret techniques and 3 ancient treasures.
During the next 130 years, Elder Lu Luo and Liu Yu had worked tirelessly to expand the Drifting Cloud Sect, and it had become one of the handful of most renowned sects in the Heavenly South Region. Her cultivation base hadn't progressed very much, but she was the most important figure in the sect below the Nascent Soul Elders due to the fact that she was essentially Han Li's spokesperson. After failing in breakthroughs to the Nascent Soul stage, she had completely given up on that, and entirely dedicated herself in assisting Lu Luo in running the Drifting Cloud Sect.
More than 4 decades later, after return from the Scattered Star Seas with the Divine Essencefused Mountain, Han Li made preparations and went into a long seclusion to make a breakthrough to Deity Transformation stage. Nangong Wan, Mu Peiling, Tian Qin'er and Shi Jian left the sect with him. Liu Yu stayed in the sect.