Well, in this fanfic, perhaps Harry's death in the graveyard could trigger some sort of magical imbalance. The Death Eaters might start fighting among themselves for power now that their main enemy is gone. Also, the Hogwarts students could rise up in rebellion against the new dark regime, in Harry's memory.
In the 'Harry Dies in the Graveyard' fanfic, his death might have a profound impact on the wizarding families. The Weasleys, who considered Harry as part of their family, would be devastated. They might even try to seek revenge on the Death Eaters. Hermione, on the other hand, could be driven to study more dark magic in an attempt to bring Harry back, which would be a very dangerous and complex journey filled with moral dilemmas.
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 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 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 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 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.
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.
The other demigods at Camp Half - Blood would also be in chaos. Percy was like a leader to many of them. His death could lead to a lack of confidence among the younger demigods. Some might even start to question the protection of the gods. Zoe's survival could also lead to her taking on a more prominent role in guiding and protecting the demigods, which is a big change from her previous situation.
Most likely, Voldemort would remain the main villain. Without Harry to stop him, he would be free to carry out his evil plans unopposed.
Well, one possible plot development could be that the Malfoys, in rescuing Harry, have a change of heart towards the whole fight against Voldemort. Maybe they start to see the error of their ways and side with Harry more openly. For example, they could use their influence in the wizarding world to help Harry gather more allies.
Perhaps the story could take a really dark turn. With Bella dead, the Volturi might see this as an opportunity to assert more control over the Cullens. They could come to Forks under the pretense of investigating Bella's death but really be there to intimidate the Cullens into following their strict vampire laws more closely. Meanwhile, Jacob could struggle with his own identity and his role in Bella's death. He might feel like he failed to protect her, and this could lead to him making some rash decisions in his werewolf form, endangering not only himself but also his pack.