It depends on personal taste. If you like the concept of a character like Tsunayoshi in the context of Dark Hunter fanfiction, you might enjoy it. Some people love seeing familiar characters in new and different fictional universes.
One common theme is the struggle with identity. Tsunayoshi, as a vampire, has to figure out who he is now and how to reconcile his new vampiric self with his old human self.
I also like the fanfiction titled 'Acheron's Redemption'. It takes a different look at Acheron's journey and how he might find true peace and acceptance. The way it weaves in new relationships for him is really interesting.
Yes, there are quite a few interesting Savitar Dark Hunter fanfictions out there. You can start by looking on popular fanfiction websites like Archive of Our Own or FanFiction.net. Some fanfictions might focus on Savitar's backstory, his relationships with other characters in the Dark Hunter universe, or new adventures he could embark on.
One idea could be exploring an uncharted area of the Dark Continent that has unique and deadly creatures not yet seen in the main series. Another could be a story about a group of hunters from different families teaming up specifically for a Dark Continent expedition, facing internal conflicts as well as external threats.
There's also 'Tsunayoshi: The Vampire Prince'. In this fanfiction, Tsunayoshi is not just an ordinary vampire but a prince of a hidden vampire kingdom. It delves into his journey of self - discovery, his duties as a prince, and his love interests. The story is filled with action, mystery, and a touch of romance.
I think 'Acheron' is very popular. It has a very complex and interesting protagonist. His story is full of mystery and pain, which attracts a lot of readers.
There are a few doujin novels with Sawada Tsuyoshi as the main character that I can recommend. Among them were "Hetalia's Tutor","(Fate/Zero Doujinshi) Tsunayoshi is Going Home","Home Tutor Tandou Tidou Tidou","Home Tutor's Other Big Sky", and "Tsunayoshi's Tragic Evolution History". These novels covered different topics and styles, and readers could choose to read them according to their preferences.
The hunter is obviously a main character. They are the ones who brave the dark and face the unknown. Another could be the various creatures of the dark that they encounter, which can be considered as important characters as they drive the action.