He could meet the ghosts of his ancestors. These ghosts might offer him some advice or reveal some family secrets that could help him in his future adventures.
In this fanfiction, Harry might encounter some strange apparitions in the graveyard. Maybe he'll find a mysterious object that has a connection to his past or some hidden magic.
The main antagonist could be a dark wizard who has made the graveyard his lair. He uses the dark energy from the tombstones and the restless spirits there to power his dark magic. Harry stumbles upon this wizard's activities and has to stop him.
Dumbledore would feel a great sense of loss and guilt. He had always seen Harry as the key to defeating Voldemort. His reaction could be to go into seclusion for a while to think about what went wrong. The other Hogwarts professors would be in shock. Hagrid would be heartbroken and might even leave Hogwarts in his grief. And the Death Eaters would be jubilant, but also a bit wary as they know that there could be unforeseen consequences to Harry's death.
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.
Yes, there are some fanfictions with such a plot. In some of these fanfictions, it might be a very dark and twisted take on the relationship between Voldemort and Harry. It could explore themes of power, control, and the blurring of the line between good and evil. However, it's important to note that these are non - canon interpretations and often deviate significantly from the original story's intended relationships.
One possible plot could be that Harry is influenced by Voldemort's false promises. Maybe Voldemort offers to bring back Harry's parents in exchange for his loyalty. Harry, in a moment of weakness and longing, decides to join him. However, once he realizes Voldemort's true nature of deception and destruction, he has to find a way to break free from this dark alliance.
Maybe Harry uses some powerful and unexpected spells. For example, he could combine the Patronus Charm with a blasting spell. The Patronus might distract Voldemort while the blasting spell hits him hard.
Well, perhaps there's a magical plant that only grows in the graveyard at Hogwarts. Harry discovers it and realizes it has the power to heal the most deadly of dark magic curses. He then has to protect it from those who would use it for evil. Or, the graveyard could be a portal to an alternate magical dimension where Harry meets versions of his friends and enemies that are very different from what he knows.
One possible motive could be to taunt Harry. Voldemort might see it as a way to show his superiority and to get under Harry's skin. It could be a form of psychological warfare.