Ice Phoenix Feng was a grade 10 Demon Beast from Ice Wave Island, a home of Ice Phoenixes. She was restricting her cultivation base to the peak of late Nascent Soul stage, because she was afraid of creating an imbalance in the Mortal Realm's origin Qi.  
Before Fairy Ice Soul ascended to the Spirit Realm, she froze over the Ice Depth Mountains for over a hundred years. Ice Phoenix Feng wanted to exterminate Fairy Ice Soul's line of cultivators in the Mortal Realm. Anyone who also had inherited Fairy Ice Soul's Celestial Ice Flames was a sworn enemy of the Ice Phoenixes.
Invasion of North Night Palace
When learning that Myriad Demon Valley was attacking North Night Palace because of a passage to the Spirit Realm, Ice Phoenix Feng joined them. Old Demon Che's incarnation led the invasion. Ice Phoenix Feng went into the fray, she faced Bai Yaoyi and Overseer Elder Yi. After few days of assaults, North Night Palace cultivators had retreated into the Spirit Void Hall for protection. Later, demon beasts have stormed into the main hall of our Spirit Void Hall with Ice Phoenix Feng's spatial powers.
As Ice Phoenix Feng battled Palace Master Liu and 2 Elders, she noticed Han Li coming out of Old Demon Che's demonic Qi space. She was willing to ignore him, if he didn't get involved in a battle, but when she noticed him using purple ice flames on his way to teleportation formation, she assumed he was from North Night Palace too and she attacked him with fury. Her white ice flames were stronger than Purple Apex Flames. Then Old Demon Che tried to entrap Han Li again, but the later sent the Unbreakable Cinque Devils to defend himself. As Han Li was facing Ice Phoenix Feng, Palace Master Liu joined him and summoned Infernal Ghost Mother. Han Li decided to use chaos and just leave through teleportation formation. Palace Master Liu wanted to stop him from leaving. Infernal Ghost Mother was scared away with Buddhist Eight Spirit Ruler. Despite Ice Phoenix Feng still trying to kill him, Han Li disappeared in the ancient one-way formation together with Ice Phoenix Feng.
Visiting Scattered Star Seas
After ending up in a sealed chamber, Ice Phoenix Feng escaped using her spatial powers, but she couldn't leave the building, because they were in the Heavenvoid Hall. After being unable to find exit, they decided to work toghether. When it was necessary for Ice Phoenix Feng to use Han Li's the Heavenvoid Cauldron, he changed his mind and decided to just wait, till the Hall will open again.
After 80 years, Han Li reached late Nascent Soul stage to Ice Phoenix Feng's enormous suprise. Then they used the control formation and forced the Heavenvoid Hall to appear. When they appeared outside the Hall, Old Devil Hun at Nascent Soul stage approached them, because he thought a valuable treasure appeared. Ice Phoenix Feng killed him easily out of frustration. Then she left to search for a way back to the Great Jin.
Leaving the Mortal Realm
Ice Phoenix Feng reached the Deity Transformation stage. Later, she learnt about the spatial node to the Spirit Realm from disciples of the Heavenly Devil Sect. After arrival at it's location in the Five Dragon Seas, she met Han Li there. At some point, the demon beast bestowed a few drops of her glacial essence upon Tian Qin'er, which cured her from Dragon Cry Physique. After 100 years of waiting in total, Ice Phoenix Feng and Han Li entered the spatial node. She used her Heaven Puncturing Ark treasure for protection. When they exited on the other side, they had been forcibly separated.
Meeting Again in the Spirit Realm
Han Li unexpectedly sees Fairy Feng once again in the Spirit Realm, except she had been caged in her spirit beast form and was presented by a desperate man at the Black Realm Exchange Convention as an auction item. She was only at the Core Formation stage and was unable to transform into her human form. Han Li found that the desperate man had also placed a seal on her, and it required a Body Integration stage cultivator to remove. She didn't think Han Li was actually a Body Integration stage cultivator since it had only been several centuries since they ascended, and believed that he reached the Spatial Tempering stage at most. After Han Li releases the seal on her using his five-colored glacial flames, she is struck with the realization that he really reached Body Integration stage. He then directs some of the true essence of the glacial flames to her dantian so she can metamorphosize. This is temporary, however, and she would need to go into seclusion to refine the true essence, or she'd revert to her spirit beast form.
When Han Li asks about how she had gotten into such a condition, she said that he was actually partially responsible. Turns out, the restrictions he planted in her body back before they ascended also activated after they were separated, and it took her close to 100 years to just barely refine them. She was severely debilitated as a result, and was targeted by a bunch of cowards [LOL]. She managed to escape through the use of a secret technique, but her cultivation base plummeted thereafter, and if that Body Integration cultivator hadn’t stepped in to save her she would most likely be dead. However, after he discovered that she was unable to metamorphosize, he treated her like a spirit beast and was preparing to make her his bonded spirit beast. She naturally refused to accept such an arrangement, so she was locked up in the cage.
She then asks Han Li if she can stay with him until she recovers her cultivation base. She knows that her current cultivation base and her identity as an Ice Phoenix would make her a target, so she makes Han Li an offer. She possesses some aptitude in formations and spatial abilities that she could use to help him, and that she would also be willing to transfer a burst of her Heavenly Phoenix Origin Yin Qi to Han Li, which should be extremely effective in improving his chances of breaking through future bottlenecks. Not to be transferred during dual cultivation though, but through a secret technique which would slightly alter the efficacy of the Yin Qi. Han Li then states his conditions, and she accepts.