Well, often in 'champion of lilith fanfic', there can be a theme of power and its consequences. The champion, being in a position of power or having special abilities due to their connection with Lilith, has to learn how to use that power responsibly. There may also be themes related to the world - building around Lilith's realm or the areas affected by her influence. This can include elements like unique magic systems, strange creatures, and different social structures that the champion has to navigate.
One common theme could be the struggle of the champion. They might face various challenges, like fighting against powerful enemies or dealing with internal doubts.
Another theme might be the relationship between the champion and Lilith. It could be a mentor - mentee relationship, or there could be some sort of spiritual connection. In some fanfics, the champion may be on a quest to fulfill Lilith's will, which could involve themes of loyalty and purpose. Also, themes of self - discovery are likely, as the champion grows and evolves in the story.