The 'Half - Blood Prince' is Severus Snape. He was a half - blood wizard, son of a Muggle father and a witch mother. His old potions book that Harry uses is filled with his own spells and notes, which is how Harry discovers his identity as the 'Half - Blood Prince' later in the story.
The Half - Blood Prince himself, though his identity might be more of a mystery or a key to be uncovered in the fanfiction. His influence through his notes and spells would be a major part of the story.
In many good fanfics, Ron is often shown as being more aware of his feelings for Hermione during Half - Blood Prince. He might be a bit clumsy with expressing them, but his loyalty to her is always clear. For Hermione, she is usually portrayed as the smart and determined one, but also with a softer side that she only shows to Ron and Harry. She might be frustrated with Ron at times, but it's always out of love.
One key element is their relationship. In a fanfic, it can be explored more deeply, like how they support each other during the difficult times of the Half - Blood Prince's year. For example, Hermione might be more protective of Harry as he gets drawn into the mystery of the potions book.
There's a fanfic where Harry and Hermione in the Half - Blood Prince time start to investigate the true identity of the Half - Blood Prince more closely. They might face some challenges that test their friendship and intelligence. It often has them using their unique skills to piece together clues from the potions book and other sources around Hogwarts.
One interesting plotline could be Hermione's discovery of new spells related to the Half - Blood Prince's notes that she uses to outwit the Death Eaters. For example, she might find a unique defensive spell that saves her friends during a battle.
One popular 'Ron and Hermione Half - Blood Prince' fanfiction is 'The Unseen Bond'. It delves deep into their relationship during that time, exploring the unspoken feelings and the tension that was building between them in the events of 'Half - Blood Prince'.
Well, Harry Potter is likely to be one of the main characters. He's always been an important part of Hermione's life in the original series, and in this fanfic, he might play a crucial role in the events related to the Half - Blood Prince. Maybe he and Hermione are on a joint mission to uncover the secrets of the Half - Blood Prince.
Well, obviously Harry and Hermione themselves are great to focus on. Harry with his courage and the mystery of his connection to Voldemort, and Hermione with her vast knowledge of magic. Their interactions and how they grow together while exploring the secrets of the Half - Blood Prince's book can be really engaging.
One interesting plotline could be Hermione's discovery of a hidden spell in the Half - Blood Prince's book that she uses to protect Harry in a dangerous situation. For example, she might find a spell that creates an impenetrable shield around them when they are attacked by Death Eaters.