One main theme is the struggle against family or social opposition. Just like in 'The Butterfly Lovers', their families' disapproval was a big obstacle. Another theme could be loyalty. For example, in stories where the lovers are separated, they remain loyal to each other no matter how long the separation is.
The theme of perseverance is common too. Lovers in Chinese love stories usually keep trying to be together in the face of various difficulties. And the theme of unrequited love can also be found in some stories, where one loves the other deeply but the feeling is not immediately reciprocated.
Another theme is sacrifice. Sometimes, one of the characters in the triangle has to sacrifice their love for a greater good. In the story of Xi Shi, Fan Li, and King Goujian, Xi Shi sacrificed her relationship with Fan Li for the political goal of helping King Goujian. She put the interests of the state (or the king's plan) above her personal love.
One main theme is the idea of transformation. Just like in 'The Butterfly Lovers' where the two lovers transform into butterflies. It shows that love can transcend human forms and continue in a different, more ethereal way. Another theme is the power of love against all odds. Despite social barriers like arranged marriages in the case of Liang Shanbo and Zhu Yingtai, their love was so strong that it overcame these difficulties.
One main theme is the struggle against feudal constraints. For example, in 'The Butterfly Lovers', Zhu Yingtai and Liang Shanbo's love was hindered by the feudal idea that men and women should not freely interact and marry according to their own wills. Another theme is the power of true love that can transcend different realms, like in 'Cowherd and Weaver Girl' where a mortal and a fairy fall in love.
Love and sacrifice. In a 'Deadly Love' Chinese novel, often one or both of the lovers are willing to sacrifice themselves for the other. This could be in the face of danger, like a deadly disease or a life - threatening enemy.
Often, there is also the theme of sacrifice. The lovers in these stories are sometimes willing to sacrifice their own well - being or even their lives for the sake of their love. In 'Xiwangmu and Dongwanggong', although their story is not as detailed, their status as celestial beings implies a certain level of sacrifice in maintaining their relationship in the celestial realm.
Love is a major theme. The love between the main characters is intense and full of challenges.
Another theme could be self - discovery. As the characters go through their love - related experiences, they also learn more about themselves, their desires, and what they truly want in life. For example, a character might realize their career goals while dealing with a love triangle.
One main theme is the struggle against fate. In stories like 'The Cowherd and the Weaver Girl', they are separated by the powerful will of the Queen Mother of the West, but they still try to be together. Another theme is loyalty. In 'Liang Shanbo and Zhu Yingtai', Zhu Yingtai remains loyal to her love for Liang Shanbo even after his death.
Since I don't know the specific content of this novel, I can't say for sure. But generally in Chinese love novels, common themes include the growth of the protagonists, the challenges in love relationships such as family opposition or misunderstandings, and the pursuit of true love.
Self - discovery is a major theme. Characters often start off not fully understanding themselves and through various experiences, they come to know their true selves better. For example, in many novels, a character might realize their passion for a certain career or hobby during the course of the story.