The Sorcerer and the White Snake

Fahai gives Xu Xian the dagger because he suspects Susu might be a demon. After observing her unique ability to heal poisons, Fahai becomes convinced she is supernatural and poses a danger to Xu Xian. The dagger is specifically designed to destroy powerful demons, and Fahai hopes it will protect Xu Xian if Susu turns hostile. However, Fahai also warns Susu to leave Xu Xian to avoid disaster, showing his conflicted feelings about her.

Earlier, Fahai noticed Susu's unusual healing abilities which raised his suspicions about her true nature.

When Fahai and his monks attack Xu Xian's home, Susu transforms into her serpent form to fight back and protect him. However, Xu Xian sees the massive snake and, believing it is a demon threatening his household, instinctively strikes Susu with the dagger Fahai gave him. He doesn't realize the snake is actually his beloved Susu in her true form. This tragic mistake leaves Susu seriously injured and triggers Xu Xian's guilt-ridden quest to find the spirit root to heal her.

Fahai's warning about Susu being a demon planted the idea in Xu Xian's mind that supernatural beings are dangerous.

After Susu's true form emerges and she attacks Fahai in anger over losing Xu Xian's memories, Fahai uses his divine Buddhist powers to confine her within Lei Feng Pagoda. This is the same prison where other wayward demons are held. The pagoda represents eternal confinement for supernatural beings who defy the natural order. Although Susu pleads to see Xu Xian one last time, and Fahai compassionately allows their final goodbye, he ultimately seals her inside, trapping her forever in her serpentine form.

Earlier, Neng Ren was assigned to capture the ice harpy and confine her within Lei Feng Pagoda, establishing it as the realm's prison for demons.

During the exorcism ritual performed by Fahai and his monks, demonic forces that had captured Xu Xian are expelled from him. When Susu uses her powers to free Xu Xian from the demonic grasp, the violent spiritual cleansing apparently erases his memories of her. The trauma of the exorcism combined with the supernatural battle leaves Xu Xian unable to remember his beloved Susu, even though their love was central to his life.

The demonic forces that captured Xu Xian during his search for the spirit root were actively trying to consume his soul.

During the battle with the bat demon king, Neng Ren is bitten by the powerful demon leader. This bite transforms Neng Ren into a bat demon himself. Despite his transformation, Neng Ren retains his human personality, memories, and fondness for human pleasures. Fahai initially tries to save him but cannot reverse the curse. Interestingly, at the film's end, Fahai accepts Neng Ren's transformation and offers him an apple, symbolizing reconciliation with his new nature.

The bat demon's bite was shown to be devastatingly effective earlier when the demon's victims were found.

Fahai accepts Neng Ren's transformation because he realizes that rigidly opposing the nature of beings does more harm than good. Throughout the film, Fahai's unwavering pursuit of demons and his attempts to protect humans from supernatural influence directly caused Susu's tragic fate. By the end, he witnesses the painful consequences of his inflexibility. When he sees Neng Ren, who retains his kind heart despite being a bat demon, Fahai chooses compassion over prejudice, symbolized by offering the apple, a gesture of acceptance and new beginnings.

Fahai's own actions with Susu demonstrated the failure of his rigid approach to demon-hunting.

Susu first encounters Xu Xian when she and her sister Qingqing are playing in the mountains. After a playful prank causes Xu Xian to fall into a lake, Susu feels sympathy for him and uses her serpent powers to give him a healing kiss that restores his vitality. This act of compassion awakens her genuine feelings for him. Later in the city, Susu deliberately seeks out Xu Xian, and they eventually fall deeply in love, culminating in their marriage. Susu's love is notable because she is willing to risk everything for a human, defying the boundaries between species.

Susu's sympathetic nature was shown when she couldn't ignore Xu Xian's misfortune after the prank.

Susu's love is forbidden because she is a snake demon while Xu Xian is a human. The movie's world operates on strict boundaries between humans and demons, enforced by Fahai and Buddhist law. Demons are supposed to be destroyed or imprisoned, not loved. Furthermore, Fahai believes that romantic relationships between humans and demons inevitably lead to tragedy, which is why he desperately tries to separate them. Susu's choice to be with Xu Xian defies these ancient laws and the natural order, making their love tragic and forbidden.

Fahai explicitly warns Susu that their union will bring disaster and threatens dire consequences if she refuses to leave.

Fahai attacks Susu because he believes it is his sacred duty to eliminate demons and protect humans from supernatural corruption. He sees Susu as a dangerous demon who will ultimately harm Xu Xian, despite her benevolent actions. Fahai is torn because he respects Susu's kindness in healing people, but his religious conviction tells him that the demon-human boundary must be maintained. When Susu refuses to leave Xu Xian, Fahai launches the attack, ultimately trapping her, believing this is the righteous path, even as it brings tragedy.

Fahai's warning to Susu about the consequences of staying with Xu Xian set up the inevitability of conflict.

At the end, Susu is permanently trapped inside Lei Feng Pagoda in her serpentine form. Before being sealed away, she shares a final tearful goodbye kiss with Xu Xian, which restores his memories of their love. However, as soon as his memories return, Fahai releases the pagoda, and Susu is drawn back into eternal imprisonment. Xu Xian is left heartbroken, spending his remaining years with the painful knowledge of what he lost. Susu's sacrifice validates her love, but she is never freed from the pagoda's confinement.

The ice harpy's imprisonment in Lei Feng Pagoda earlier established this as the fate awaiting wayward demons.

Qingqing helps Neng Ren discover the bat demon king's location because she develops a connection with him despite his human status. When they first meet, Neng Ren is still human, and Qingqing is curious about him. Even after Neng Ren becomes a bat demon, Qingqing continues to interact with him, showing that she doesn't judge him by his species, mirroring her sister's love for Xu Xian. At the film's end, Qingqing tells Neng Ren she never wants to experience deep love like her sister did, hinting at her complex feelings about their relationship.

Qingqing's initial curiosity about Neng Ren when they met in the city foreshadowed their ongoing connection.

The ice harpy encounter serves as an introductory sequence that establishes key elements: Fahai's role as a demon hunter, his loyalty to Neng Ren, and the existence of Lei Feng Pagoda as a demon prison. The whimsical ice harpy also sets the film's tone, blending playful fantasy with darker supernatural threats. More importantly, this quest to help Nengren leads Fahai to cross paths with Xu Xian, whose boat they take to the city. Without this chain of events, Fahai may never have encountered Susu and become entangled in the central tragedy.

The harpy's imprisonment in Lei Feng Pagoda directly parallels Susu's later fate.