A common theme is the music collaboration. Since they are both in the music industry, fanfics often imagine them creating a hit song together. It could involve them in the studio, sharing ideas, and the creative process.
One tip is to build a good vocabulary in both Visayan and English. This helps you find the most accurate equivalents. Another is to study the cultural nuances of Visayan. For example, certain traditions or beliefs in Visayan might need special handling in translation. Also, don't be too literal. For instance, if there's a Visayan expression that's very metaphorical, find an English metaphor that conveys a similar meaning.