The plot could start with Harry escaping the Dursleys earlier than in the original. He then roams around, trying to find a place to belong. He might stumble upon some hidden magical secrets in the Muggle world that are related to his parents. As he grows, he starts to attract the attention of both good and bad wizards. Some might want to help him, while others see him as a threat because he's an unknown factor, not following the normal wizard upbringing.
One way the plot could develop is that Harry, while raising himself, discovers a new form of magic that is considered lost in the wizarding world. This makes him a target for dark wizards who want to use it for evil. Meanwhile, he tries to find out more about his parents through his own investigations. He meets some old friends of his parents who teach him about the wizarding world in a different way than Hogwarts would. He has to constantly fight off the dark forces while also trying to figure out his place in the world.
The plot could start with Harry being found by a samurai clan. He'd grow up learning their ways. Then, when he discovers his magical heritage, he has to blend the two worlds. Maybe he uses samurai skills to fight dark wizards.
In this fanfiction, the plot might revolve around Harry's struggle to balance Kreacher's teachings with the values of the wider wizarding world. He could face discrimination from other wizards who are suspicious of his upbringing. Meanwhile, Voldemort might see Harry as an even greater threat because he's been raised by Kreacher. Kreacher, being protective, tries to shield Harry from the Dark Lord, but Harry realizes he has to take a stand. This could lead to a series of battles and adventures where Harry has to prove himself not just as a wizard, but as a person with his own set of beliefs.
In this fanfiction's plot, Harry's identity as the Boy Who Lived would be intertwined with his military upbringing. He could start a sort of 'wizarding army' within Hogwarts, recruiting students who are willing to fight against the dark forces. His training by soldiers would make him a natural leader in this regard. The story would then revolve around his efforts to build this army, face the opposition from some traditional wizards, and ultimately use this new force to defeat Voldemort in a more strategic and coordinated way.
The plot could start with Harry being born on a spaceship or a space colony. As he grows, he discovers his magical powers, which are different from those on Earth. He then gets a message or a sign that leads him to a quest. This quest might involve finding a lost magical object that has the power to save the space - wizarding community from a dark force. Along the way, he meets other magical beings from different parts of space and they form a team to complete the mission.
The plot could involve Harry using his magic in a more open way around the Dursleys. They might help him hide it from the wizarding world until he's old enough to go to Hogwarts. Then, at Hogwarts, he could be more focused on learning for the joy of it rather than as an escape from his horrible home life.
The plot might start with Harry being taken in by Pitch Black at a very young age. Then, he would be taught things that are not part of the normal Hogwarts curriculum. As he grows older, he might start to question the motives of Pitch Black. This could lead to a conflict between them, and Harry could decide to break away and find his own path in the wizarding world, perhaps with the goal of using his unique skills for good.
In the later part of the plot, there could be a turning point. Maybe Harry realizes that his isolation isn't helping him and that he needs his friends. Or perhaps an external threat arises that forces him to come out of his self - imposed isolation. This could lead to a rekindling of his relationships, and they all work together to face the new challenge stronger than ever before.
In this fanfiction, Harry's development could be centered around his understanding of family. Growing up with a scorpion, he has a very different concept of what a family is. This could lead to him having a complex relationship with the Weasleys or other surrogate families in the wizarding world. He might be hesitant to accept their love and care at first, but gradually come to realize the value of a real family. Also, his magical development could be more instinctive, like how a scorpion reacts instinctively to threats, Harry might use magic in a more impulsive yet effective way when in danger.
Harry would likely develop a very different personality. He may be more solemn and less prone to the typical teenage angst that the original Harry had. Since he is raised by Death, he might be more in tune with the darker aspects of life and magic from a young age.
Well, perhaps the plot could involve Harry having to fend for himself from a very young age in the wizarding world. He might have to figure out magic on his own, without much guidance from adults. Maybe he starts exploring the secrets of Hogwarts by himself earlier than in the original story, leading to all sorts of unexpected adventures.