Hermione might be the one. With her extensive research skills and vast knowledge of magic, she could have stumbled upon a way to remove the scar. She was always determined to help Harry, and this would be just another of her great contributions.
In the fanfiction, perhaps Harry would finally be free from the constant reminder of his encounter with Voldemort. His life might become more normal, without the stares and whispers related to the scar. He could focus more on his own growth and development as a wizard, rather than being defined by his past trauma.
One interesting scenario could be that the removal process involves a unique magical spell that only Harry, with his special connection to Voldemort, can perform. This spell might require him to draw on his deepest reserves of courage and love for his friends.
One interpretation could be that the scar is a physical manifestation of the threat of death that has always loomed over Harry. Voldemort's attempt to kill him as a baby left a mark that is constantly a reminder of that near - death experience. It could also symbolize that Harry has a connection to death in a more mystical way, like being able to sense when death is near or having a certain immunity to some of the more terrifying aspects of death magic because of his own encounter with it at such a young age.
In 'Harry Gets His Inheritance' fanfic, Harry may get some really cool magical items as part of his inheritance. Maybe a wand that has special powers or a cloak that has enhanced invisibility. His inheritance could also include knowledge, like a hidden library full of rare magic books. This knowledge would make him a much more powerful wizard. And it might also lead to some interesting relationships. For instance, he could be related to some powerful wizarding families through his inheritance, which would change the way others in the wizarding world view him.
It can introduce a darker and more mysterious element to the plot. For example, if Harry discovers that he has death in his scar, he might become more withdrawn as he tries to understand what it means. This could lead to him isolating himself from his friends, which in turn affects the group dynamics.
Obviously, Harry is the most important character. Then there might be his friends like Hermione and Ron. They could help him understand and manage his inheritance. There may also be some new characters, like an old wizard who is the keeper of the inheritance until Harry is ready. And of course, the antagonists like Draco Malfoy or any remaining Death Eaters might be interested in his inheritance, either to steal it or to stop Harry from using it to gain more power.
He might initially be confused. Harry could keep trying to engage with his friends as usual, not really understanding why they are being cold towards him.
He might lash out with his magic. For example, he could send a spell flying at the source of his anger without really thinking. Sometimes, he just glares intensely, his green eyes filled with fury. And he may raise his voice, shouting at those who have angered him.
He might be initially heartbroken. Harry has always been a bit of an emotional person, so he could go into a state of depression for a while. He might isolate himself from his friends and focus only on his studies or fighting against the dark forces, using it as a way to distract himself from the pain of the rejection.