One common theme is the exploration of their different worlds. Thor from Asgard and Black Widow from Earth. Writers often use this to create interesting cultural clashes and exchanges.
One common theme is friendship. Since they are both Avengers, many fanfics explore how they become friends and support each other. Another theme is adventure. They often go on exciting missions together in the fanfics. And there's also the theme of mutual respect. They both have unique skills and personalities, and fanfics often show how they respect each other's abilities.
One common theme is empowerment. The black woman character is often shown as strong and capable, whether it's in combat or in providing wisdom to Thor. Another theme could be cultural exchange, as her background may introduce new ideas to Thor's world.
One common theme is the exploration of their different worlds. Thor from Asgard and Black Widow from Earth have very distinct backgrounds, and fanfictions often play with how they bridge that gap.
There could be various interpretations in such a fic. One possibility is that it shows Loki's complex character development. His childhood abuse might have led to his feelings of inferiority and envy towards Thor. For example, it could be used to explain why he sometimes acts out in a negative way, as he is constantly trying to prove himself after such a traumatic childhood.
One popular 'thor black woman fanfiction' might be found on platforms like Archive of Our Own. You can search for tags related to Thor and black female characters. There are often stories that explore different relationships and adventures involving Thor and a black female lead, which can be really interesting to read.