Well, perhaps in the fanfiction, after Harry's death, Hermione discovers some hidden power or knowledge that Harry had been protecting or researching. This new discovery could lead her on a journey to avenge Harry and also to save the wizarding world from an impending doom. Maybe she teams up with Ron and other friends, but she's now the driving force, having been changed by Harry's sacrifice.
In a 'harry potter dies saving hermione fanfiction', it could be that the wizarding world mourns Harry's death in a big way. Hermione, on the other hand, might struggle with her own feelings and at the same time face the wrath of some who blame her for Harry's death. She could then have to prove herself and show that Harry's sacrifice was not in vain. There could also be a sub - plot where the magic itself seems to react to Harry's death, creating some sort of imbalance in the wizarding world that Hermione has to fix, all while dealing with her personal grief and the expectations placed on her.
One possible plot development could be that Hermione is left with a deep sense of guilt and responsibility. She might then take on Harry's mission or cause in his memory. For example, if they were fighting against a new dark wizard, Hermione could become even more determined to defeat the enemy.
One possible plot development could be that Voldemort fully regains his power without Harry as an obstacle. The wizarding world would be plunged into complete darkness. His friends, like Hermione and Ron, might go into a deep state of despair and then form a resistance group. They would try to find other ways to defeat Voldemort, perhaps by seeking out more powerful magical artifacts or uniting with some previously neutral magical creatures.
One possible plot development could be how the wizarding world reacts to the loss of the so - called 'Chosen One' even as a baby. There might be widespread grief and fear among those who opposed Voldemort, as they had placed so many hopes on Harry. Another aspect could be how Voldemort's reign of terror continues without the threat of Harry Potter. He might become even more powerful and tyrannical, with no one to oppose him in the way Harry was prophesied to.
One possible plot development could be that Sasuke is in a life - threatening situation, perhaps against an extremely powerful enemy. Naruto sacrifices himself to give Sasuke a chance to escape or defeat the foe. This would likely lead to Sasuke being filled with guilt and regret, and might change his whole outlook on life.
One possible plot development could be that with Harry's death, Voldemort fully takes over the wizarding world. His reign of terror becomes absolute, and the remaining characters have to go into hiding or form a secret resistance. For example, Hermione might lead the resistance, using her intelligence to try and find a way to defeat Voldemort without Harry. Another aspect could be the emotional turmoil among the characters. Ron would be devastated, and his character could either sink into depression or be driven by a thirst for revenge. Ginny, too, would have to deal with the loss of her love and might become a more hardened and fierce fighter against the Dark forces.
One possible plot development could be that his friends are left to pick up the pieces. They might struggle with grief and guilt, thinking they could have saved him. Another could be that Voldemort finally takes over completely without Harry to oppose him, leading to a dark reign over the wizarding world.
One possible plot development could be that a powerful magical creature or a hidden ally steps in at the last moment to save Harry. For example, a phoenix might appear and drive the dementors away with its purifying fire.
Finding a particular 'harry potter dies saving hermione fanfiction' can be a challenge. Some fanfictions explore darker themes like this, but they are not always easy to spot. Another place to look could be Wattpad, although it has a very large collection of stories, so you'll need to be patient while searching. You can also narrow down your search by adding more tags related to the story, such as the Hogwarts house of the characters or the specific situation in which Harry dies to save Hermione.
Perhaps during the rebuilding, Harry has to deal with various magical creatures that have made the ruins of Potter Manor their home. He might have to find a way to relocate them without harming them. Also, he could be visited by friends from Hogwarts who offer their help and in the process, there are some interesting interactions and exchanges of magic knowledge.
One possible plot development could be that his death shatters the Straw Hat crew. They might disband in grief, each going their own way. Zoro could become consumed with revenge, vowing to take on the Marines who were responsible.
One possible plot development could be that Dark Harry has some ulterior motive for kidnapping Hermione. Maybe he wants to use her knowledge to further his dark plans. For example, Hermione is known for her intelligence and vast knowledge of magic, and Dark Harry might force her to help him find a powerful and dark magical artifact.