Han Bei is one of the recurring characters in I Shall Seal the Heavens. She is a major antagonist in the series. She is a beautiful cultivator from the Black Sieve Sect who once had Meng Hao cooperate in her schemes within the tombs of her sect's Blessed Land.
She is a descendant of the Han Clan, a clan that no longer exists and one of the nine clans that rebelled against the Ji Clan. It is unknown whether this Han Clan has a relation to the Han Clan of the Eighth Mountain and Sea.
She was once from the Black Sieve Sect, one of the former five great Sects. During the opening of the Blessed Land, she approached Meng Hao to join her and a couple other people to find some good fortune in the tombs of the Blessed Land.
Han Bei and a few of her allies planned to use the other cultivators, which would lead to their death. Meng Hao figured this out and foiled their plans. In the end, only Meng Hao and Han Bei were left of the former six members.
During the Song Clan search for a son-in-law, Meng Hao revealed that he had, in fact, recorded Han Bei killing her fiance, a conclave disciple of the Black Sieve Sect. He used this to bring Han Bei in line when she tried to use Xu Qing to threaten him.
During his time as Fang Mu in the Violet Fate Sect, Meng Hao along with Zhou Dekun, visited the Black Sieve Sect to give lectures on alchemy. There, Meng Hao noticed that Han Bei was acting weird and learned that many disciples of Black Sieve Sect had been infected with discarnate souls who were attempting to possess them. Meng Hao, also, figured out that while on the surface Han Bei acted like she was the discarnate soul, in fact she was the one in control. Moreover, she had the soul of the Han Clan ancestor inside of her, as well. It is assumed she made contact with him back in the Blessed Land.
Later, when Meng Hao went to eradicate the Black Sieve Sect, he found that Han Bei was nowhere to be found. Also, it seemed like most people had no recollection of anyone named Han Bei at all.
At the bottom of the Sea pressure trial by fire of the Nine Seas God World, Meng Hao saw a corpse, presumably of an Ancient God (See Renegade Immortal for details). Surprisingly, on top of its head, Meng Hao saw Han Bei for a fraction of a second before he was ejected by the sea pressure.
Her next appearance was after a thousand years with her entering the Vast Expanse School. She became one of the several Holy Daughters in one of the sects within the school. Hearing about the genius of the Ninth Sect, Fang Mu (Meng Hao's clone who was ascending to the Immortal Realm at the time), her curiosity was irked as the name sounded very familiar. She, however, was very much shaken after seeing both Fang Mu and Meng Hao. Meng Hao saw her and he too was shocked at sensing the 'Allheaven' aura on her. The exact nature of her relation to the Allheaven is yet to be uncovered.
She was the one that trapped the rest of Chu Yuyan's soul that Meng Hao was unable to locate, as he could only recover a bit of her soul. To prevent the soul from dissipating, she would infuse a bit of her life force every now and then; eventually their souls became symbiotic. She used this as leverage against Meng Hao, temporarily arousing his anger.
Han Bei is an ally of Allheaven and is, in fact, A Daughter of Allheaven. As an agent of Allheaven, her purpose is to induce Demons into becoming the emissaries of Allheaven known as Sons of Allheaven. She has to induce immortal tribulations on every Sons of Allheaven to help recover Allheaven's body. She tried to trick Meng Hao; however, the latter managed to escape that fate due to the help of the Copper Mirror, the Bronze Lamp, and Lord Fifth.
Afterwards, Meng Hao returned to the Vast Expanse School and unleashed a killing intent so frightening that it made even the other four potentate and the 9-Essences paragons back down. Meng Hao attacked Han Bei with no holds barred and managed to kill her clone in both body and spirit. However, due to Yan'er living with Fang Mu (Clone)'s ninth life, she was able to sense her position through her connection to Chu Yuyan's soul. She rushed to use Yan'er as a bargaining chip to save herself, however, Meng Hao appeared and slashed the Karma thread connecting her to Chu Yuyan's soul, which allowed Meng Hao to use the Copper Mirror to completely sever the connection between Han Bei and Chu Yuyan's soul.