As of now, Uta is indeed alive. The story hasn't depicted anything otherwise. Maybe there'll be changes in the future, but for now, Uta's part in the manga continues with them being alive.
Another plot could be a story about their relationship development. It might start with them not getting along very well, Kokichi constantly teasing Himiko. But as time passes, they gradually realize they have more in common than they thought. They could then start to support each other in difficult times, like when facing threats from other characters in their universe.
There could be other authors who are known for their unique takes on the pairing. Maybe an author who likes to put Kokichi and Himiko in unexpected situations, like in a high - school AU (alternate universe) where they are both students. This author might be really good at adapting the core personalities of the characters to a different setting and still making their relationship believable and interesting. So, different people might consider different authors as the 'best' depending on what they like in a fanfiction.
Saya no Uta Visual Novel is often known for its distinct narrative. It might include elements like complex character relationships, a particular setting, and a series of events that the player gets to experience. It could be about a journey, a mystery, or some sort of emotional exploration, but again, this can vary depending on the specific content of the visual novel.
I would recommend 'Uta's Hidden Affection'. In this fanfiction, the development of the relationship between Uta and the reader is really interesting. It starts with small interactions that gradually build into something deeper. The description of Uta's character is very accurate to his original personality in the source material.